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break pedal to the floor; 1995 Buick Skylark, no ABS lights


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fat-katie
User

Jun 4, 2021, 4:54 PM

Post #1 of 21 (485 views)
break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

1995 Buick Skylark, 3.1
The pedal suddenly just went to the floor. No brake pressure.

After bleeding the brakes; no joy. So I changed the master cylinder. If you are familiar with it (DM ABS VI system) the master has 4 ports. How do you bleed it?

I couldn't do it, so I just reattached the master cylinder to the ABS body (with the ABS modulator's pistons 'HOMED' at the top). That should allow a brake bleed, which it did.

Car on ... no ABS or brake lights. Now the ABS may not work yet, but the brakes should function. Right? They don't move and the pedal goes right to the floor.

With the engine off, the pedal gets stiff again. In fact I used it to bleed the brakes.


(This post was edited by fat-katie@outlook.com on Jun 4, 2021, 4:55 PM)


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Jun 4, 2021, 5:13 PM

Post #2 of 21 (481 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

Here are the instructions from the service manual.

MANUAL BLEEDING
Note: Use only DOT 3 brake fluid from a clean, sealed container. Do not use fluid from an open container that may be contaminated with water. Do not use DOT 5 brake fluid.

Important: In the following steps, use a suitable container and/or shop cloths to catch fluid and prevent it from contacting any painted surfaces.

1. Clean fluid reservoir cover and surrounding area.
2. Remove fluid reservoir cover.
3. Inspect fluid level in reservoir and fill to the correct level if necessary.
4. Install fluid reservoir cover.





5. Prime hydraulic modulator as follows:
A. Attach a clear bleeder hose to the rearward bleeder valve and submerge opposite hose end in clean container partially filled with clean brake fluid.
B. Slowly open rearward bleeder valve 1/2 to 3/4 turns.
C. Depress brake pedal and hold until fluid begins to flow.
D. Close valve and release brake pedal.
E. Repeat Step 5B through 5D until no air bubbles are present.
F. Relocate the bleeder hose to the forward hydraulic modulator bleeder valve and repeat Steps 5A through 5E.

Important: Once fluid is seen to flow from both modulator bleeder valves, the hydraulic modulator/master cylinder assembly is sufficiently full of fluid. However, it may not be completely purged of air. At this point move to the wheel brakes and bleed them. This ensures that the lowest points in the system are completely free of air and then the hydraulic modulator/master cylinder assembly can be purged of any remaining air.

6. Remove fluid reservoir cover.
7. Inspect fluid level in reservoir and fill to the correct level if necessary.
8. Install fluid reservoir cover.
9. Raise vehicle and suitably support.

Important: Bleed sequence:

Right rear.
Left rear.
Right front.
Left front.

10. Proceed as follows to bleed wheel brakes in sequence shown above.
A. Attach a clear bleeder hose to the bleeder valve at each wheel and submerge opposite hose and in a clean container partially filled with clean brake fluid.
B. Open bleeder valve.
C. Slowly depress brake pedal.
D. Close valve and slowly release brake pedal.
E. Wait 5 seconds.
F. Repeat Steps 10B through 1OE until the brake pedal feels firm at half travel and no air bubbles are observed in the bleeder hose.

Note: To assist in freeing entrapped air, tap lightly on caliper with a rubber mallet.

11. Repeat Step 10 on left rear wheel brake.
12. Repeat Step 10 on right front wheel brake
13. Repeat Step 10 on left front wheel brake.
14. Lower vehicle.
15. Remove fluid reservoir cover.
16. Inspect fluid level in reservoir and fill to the correct level if necessary.
17. Install fluid reservoir cover.
18. Bleed the hydraulic modulator.
A. Attach a clear plastic bleeder hose to the rearward bleeder valve on the hydraulic modulator. Submerge opposite hose end in a clean container partially filled with clean brake fluid.
B. Depress brake pedal with moderate force.
C. Slowly open rearward bleeder valve 1/2 to 3/4 turns and allow fluid to flow.
D. Close valve and slowly release brake pedal.
E. Wait 5 seconds.
F. Repeat Steps 18B through 18E until no air bubbles are observed in the bleeder hose.
G. Relocate the bleeder hose on the forward hydraulic modulator bleeder valve and repeat Steps 18A through 18F.
H. Tighten hydraulic modulator bleeder valves to 9 Nm (80 lb.in.).
19. Remove fluid reservoir cover.
20. Inspect fluid level in reservoir and fill to the correct level if necessary.
21. Install fluid reservoir cover.
22. With ignition "ON" apply brake pedal with moderate force and hold. Note pedal travel and feel. If pedal feels firm and constant and pedal travel is not excessive, start the engine. With the engine running, recheck the pedal travel. If it's still firm and constant and pedal travel is not excessive, go to Step 23. If pedal feels soft or has excessive travel either initially or after engine start, perform the following: With a Tech 1, "Release" then "Apply" each motor 2 to 3 times and cycle each solenoid 5 to 10 times. When finished, be sure to "Apply" the front and rear motors to ensure the pistons are in the upmost position. DO NOT DRIVE THE VEHICLE. If a Tech 1 is not available, remove foot from brake pedal, start the engine and allow it to run for at least 10 seconds to initialize the ABS. DO NOT DRIVE THE VEHICLE. After 10 seconds, turn the ignition "OFF." This initialization procedure MUST be repeated 5 times to ensure any trapped air has been dislodged. Now repeat bleeding procedure starting at Step 1.
23.Road test the vehicle. Make several normal (non ABS) stops from a moderate speed to ensure proper brake system function. Allow adequate cooling time between stops.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



(This post was edited by Hammer Time on Jun 4, 2021, 5:13 PM)


fat-katie
User

Jun 4, 2021, 6:50 PM

Post #3 of 21 (469 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

I'm 5 cycles into this now (no brake bleed) and after the bleed of the fore and aft modulator ports, the pedal goes to the floor AFTER the engine start.

After I home/bleed again (5 starts, 15 second running time) the first pedal bleed of the aft port is all air. The pedal is unloaded in this first bleed. It comes right back after it. The second bleed is good (very small amount air) I got to the point of not 5 cycling at all since the engine start unloaded the pedal.


It's like the engine is pumping air into this. Maybe the ABS requires more cycles. I'll try.

I can't see any leaks. All hydraulic connections are sound (or so I believe).

Aside. The first attempt to bleed the fore port produced no fluid. Turns out the valve was clogged with rust. Not good I think.

Thank you for your help.


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Jun 4, 2021, 7:31 PM

Post #4 of 21 (456 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

You would probably do a lot better if you used a pressure bleeder.

I meant to tell you before, you should immediately change your user name before the spammers get hold of it.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



fat-katie
User

Jun 5, 2021, 8:17 AM

Post #5 of 21 (431 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

Well I'm off to salvage. There is something that's not right in the modulator section. I'm looking at the video at utube (search "Buick - ABS Update: ABS VI (1996)" ) and I can't understand the failure mode. Seems the ABS cannot defeat breaking. Why the engine unloads the pedal is a mystery.


I hope the ABS 6 found in the century and regal models are compatible.


Hammer Time
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Hammer Time profile image

Jun 5, 2021, 8:28 AM

Post #6 of 21 (423 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In


Quote
Seems the ABS cannot defeat breaking.


Not sure what you mean there. How are you testing?


Quote
Why the engine unloads the pedal is a mystery.


That would be the vacuum assist doing that. It means you haven't got all the air out yet or one of the valves is not sealing properly.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



(This post was edited by Hammer Time on Jun 5, 2021, 8:28 AM)


fat-katie
User

Jun 5, 2021, 8:45 AM

Post #7 of 21 (417 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

What I mean by an unloaded pedal is that when it is pushed, it goes to the floor without ANY resistance. After a bleed cycle and before the engine is started the pedal is solid. I expect that. There is no assist.


Now I start the engine, let it run, don't touch the pedal, and then shutdown. With the engine off, the pedal is now unloaded again (Doh! The vacuum is still up). But never mind that ... On the next bleed, one whole pedal's worth of air comes out of the aft port. Only the ABS moved so I assume that's where the air came from. I've bleed this 10 times. There is more air in there?


I'm checking for leaks very closely and I don't see any.

It's a trip to the yard so I'll bleed this 10 more times.

Thank you for all your help.


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Jun 5, 2021, 8:55 AM

Post #8 of 21 (411 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

???? 1995 Buick, just that model year was doing some funky things like 1st (just some) had OBDII. All would next model year. No real matter this, as HT is saying is air in the system or defective master? Did it bench bleed OK?
Plain bleeders at wheels: If/when one or more doesn't behave, take that one out if they don't snap off and with a drill you can open it up as new, clean threads up and check the pointed end. IF no good take it with you for a new one, this old parts may have used other types.
Pedal to floor means it's just squishing air somewhere. Hard to find you could plug master and see if you can get a full pedal without any other brake parts involved to FOR SURE rule that out,


T



Hammer Time
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Jun 5, 2021, 8:56 AM

Post #9 of 21 (411 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

It can be hard to get all the air out of the modulator. You may ultimately need a professional scan tool to cycle the solenoids as per these instructions.


With a Tech 1, "Release" then "Apply" each motor 2 to 3 times and cycle each solenoid 5 to 10 times. When finished, be sure to "Apply" the front and rear motors to ensure the pistons are in the upmost position. DO NOT DRIVE THE VEHICLE



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



fat-katie
User

Jun 5, 2021, 3:24 PM

Post #10 of 21 (387 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

I finally got the air out but still have a 'dead' pedal with the engine running.

I took everything off and will inspect everything. I'd just like to note the master cylinder install procedure.

Note that this new master acted exactly the same as the replaced unit.

Unlike normal masters with two ports ( not counting the reservoir ports ), this unit has 4 ports so there is no priming possible as far as I can see. Two bleed connectors were supplied but the fluid just runs out of the other two lower ports. These two lower ports are connected to the module via "transfer tubes" It looks like the bleed should be accommodated threw the abs module.


There is something rattling in the module which could be ok. There are lots of moving parts in there.

I'll let you know. Probably going to the salvage yard.

Thanks for the help


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Jun 5, 2021, 4:10 PM

Post #11 of 21 (383 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

Two notes and a trick One could make new master a failure!
1. You bench bleed master cylinders if it take 4 bent tubes or just two. If you don't have those threaded flare nuts just buy whatever fits in pre made 1 or 2 foot sections with correct flared line too. Cut and bend back so it refills master. If you didn't touch it, no telling how dry it was new (some states allow reman ones) could or would tear the crap out of the rubber seals inside. Game over for that one.


2. Did the same as the last would suggest it wasn't that but not bleeding master NEW is a problem. It's just squishing air right in it unseen pumping away is just exercise.


The trick? Some are at such an angle in vehicle it's hard to quick hook up with plugs in those ports fast so you allow some air.
Trick is you pull a wheel from front and another from rear. Now push back even while installed on a brake pad watch it push fluid backwards. Same with rear if disc? If not, set parking brake before you ever started anything AND push brake pedal. Release when done that push some fluid back to master. If not enough you can squeeze wheel cylinders via the tabs that push shoes.
If you plugged off all four for a test (use line you just got and bend in a vice if need be for plugs. Then know it's NOT the master.
Engine on or not is just assist not required for the pumping pedal way of bleeding brakes - with a helper you don't let go of pedal till bleeders are tight again then do again. If not you just sucked air backwards from anywhere open still,


T



Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Jun 5, 2021, 4:54 PM

Post #12 of 21 (376 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

Tom, are you aware of what system he has here?






~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
Ultimate Carjunky / Moderator
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Jun 5, 2021, 5:36 PM

Post #13 of 21 (372 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

Thanks! Now I can go puke. Some leftover AMC failure designed mess. Fred and Barney could do better
:-)
It's still just going to the floor suggests air isn't out. My reply was ways it could wreck the show,


Tom


fat-katie
User

Jun 6, 2021, 12:45 PM

Post #14 of 21 (333 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

Give me credit for coming clean..... it's was a brake line! On inspection they all need to be changed. There are no brake line kits available. Seems like a big job. I might have to junk her.

There was so little fluid leaked that I suspect that once it sucked in some air it stopped leaking. If it were up on a hoist it would have been obvious.

Thank you for all the help and sorry I wasted your time. I know a lot about ABS now.

FYI A 1997 Skylark, at the yard, had almost the identical ABS setup. It only had one connection to the modulator so I couldn't use it. When asked if they ever get 95s the guy said no.


Tom Greenleaf
Ultimate Carjunky / Moderator
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Jun 6, 2021, 1:19 PM

Post #15 of 21 (329 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

No problem sport. Brake line isn't so costly it's more making it up and routing it as it was or risk of it rubbing. Most vehicles also put a coil like a spring off master cylinder I think so it doesn't but off easily in a collision? Duplicate what is there.


There's lots in ABS cars there's a nack to bending line if not available in sections to do all like you said. Takes time more than the parts depending on some if it busts something else to do it.


One body larger they also put a trans line up front where it can be rusted or harmed with a cooler too that rusted the LeSabre body this model year exactly.


Just find the right shop is what I suggest it's a pest more than parts as said. Good luck if fuel and vapor lines are just as bad you've got to think seriously about this car rust can end all games and be not worth it vs another car!


Tom



fat-katie
User

Jun 6, 2021, 2:21 PM

Post #16 of 21 (323 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

After a few videos on copper nickel lines and a poke around. Yah, this is a job. But I have the time. I'm going to give it a shot.

I don't know how to close this thread but I consider it closed.

Expect another one as I dive into these brake lines.


Thanks all. Out


Tom Greenleaf
Ultimate Carjunky / Moderator
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Jun 6, 2021, 2:52 PM

Post #17 of 21 (315 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

Search out what I call an "IMP" cutter for line and a flaring tool. Now choose types of "tubing benders" if you take out one section at a time duplicate that to where you can make a "union" is what I do.


There are choices of types of line I personally like buying already made super long ones and a couple short ones just for the flare nuts is cheaper that way for me. Not so much a fan of whole rolls of line and find your own flares - some will be different at one end than the other so save those if at all possible.
The tools aren't even all that costly except maybe the "IMP" by I like the old now "Blue Point" one made by Snap-On. If a cheap cutter walks down line you are just wasting more time.
Try to save all the things that hold line in place! Can be flaps of metal or assorted should be obvious to you. If those bust some thought and cushioned wire loom holders can work well.


It's all time. You said you have. YOU probably do NOT have to replace 100% of it just tricky to each flex hose that goes to wheels also can bust, a horseshoe clip usually AFTER you get old line out.


Sorry for the book on it, it's doable just time. Be careful of long stretches they can't vibrate with the car. Add a holder if needed.
Double check for fit and leaks as soon as possible when done. Connection run a finger UNDER those make sure or a flare you made.


Good luck. Nicer if you know overall rust scene and think hard if it's just this or lots of other things just waiting to be the next pest up to unsafe ALSO!


Come back if thread is lost and let us + the world know how much FUN it was :-)
Tom



Hammer Time
Ultimate Carjunky / Moderator
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Jun 7, 2021, 2:07 PM

Post #18 of 21 (291 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

I think you are going to be in for a surprise when you realize just how much work this actually is.

DO NOT use and compression fittings. Everything has to be double flared and threaded together.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



fat-katie
User

Jun 20, 2021, 2:34 PM

Post #19 of 21 (201 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

This was a lot of work. All the brake lines are changed. There are no leaks and there is no air. After a million bleeds, and ignition cycles it finally works.

The biggest problem I had was making a bubble flare. After, literally, making 20 of them I came up with this method.


The kit was a Performance Tool flaring kit of ISO/Bubble, W80672.

Putting the tool in a vise make all the following much easier. You have much better control.

There is a wrench included with this kit that has a notch to measure the line length exposed for flaring in the clamp. The length is 15/64. There is no way exposing that much line will get you a good flare. I had to pull it in a bit.

In clamping I kept the bars planar. I used the wrench on edge to insure it.


I also found a minimum clamping force that didn't damage the line much. First, I snugged in the line with one of the two clamping bolts. I did this while keeping the two bars as parallel as possible. Then I finished the clamping by wrenching the other bolt down. For my 3/16 line there was quite a bit of space left between the bars.

In the last step I did not press the die all the way to the bar, but stopped when I got a step in the force required to form the flare. There wasn't much space left between the die and the bars. The die was also greased (I saw a video where someone used oil.)

Number one tip? Don't use the wrench to measure your tubing in the clamp.

This is all from a rookie. This worked for me but it may all be wrong. None of my fittings leaked. (lol they may in the future)


Thanks for all the help. I've got a car now.


Hammer Time
Ultimate Carjunky / Moderator
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Jun 20, 2021, 2:44 PM

Post #20 of 21 (197 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

Yep, that's just the basic, manual flaring tool. They definitely are hard to use.

This is what I use. You can make fuel line quick connects also.





~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Jun 20, 2021, 3:31 PM

Post #21 of 21 (190 views)
Re: break pedal to the floor; 1995 Buick Skylark, no ABS lights Sign In

fat-katie! I give you 5 STARS for the effort AND success. It's doable yet know the time and frustration oh too well. It's hard to do this for "other" vehicles for a job it would take me too much time to tie up a vehicle plus wouldn't know how to charge even by the hour without some outrageous bill so refuse those (once not so almost retired) can't make another, one/two day job wait as I worked alone except in the 1970s and not for all that long on to my own shops.
Serious, all the credit in the world, this isn't something most DIYer would take on with the vigor you gave it!
Check for leaks but trust you have also check if lines rub anywhere can wear thru a new one. If any assorted holders (some can be just bending spot welded things see what you can create in that area so work.


Good luck, if it's right you'll be giving the suggestions to others or WARNINGS it's a pest of all pests if only because locations the OE stuff was mostly in place before vehicle was finished assembly YOU can't do that again,


Tom






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