Question about 1995 Buick LeSabre

1 Answer

While sitting at a traffic light the brake pedal slowly goes down. One pump and it comes back up to normal and holds. This is a '95 LeSabre very low mileage (31,000) very clean car. No signs of brake fluid leaking anywhere. Help?

Posted by on

  • Teamsternip Apr 05, 2011

    Sounds like a good place to start. Makes sense. Thanks for the advice AND the quick response. It's appreciated.

  • Teamsternip Apr 21, 2011

    Got the problem resolved. It was a bad master cylinder. The brake fluid sure was funky too. I wouldn't doubt it was the original DOT3 fluid from 1995. Thanks again for your time and your advice.



1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Buick Master
  • 17,130 Answers

There might not be a leak but I think there is AIR within the hydraulics. So if you have not checked your brake hydraulics for a very long time, it is good to check the master and brake cylinders.
Finally you need to BLEED out the air so that on the first pump you get a hard pedal.
Check at the wheels for possible smear of fluid indicating small leak and air intake.

Posted on Apr 05, 2011

Testimonial: "Sounds like a good place to start. Thanks for the advice and the QUICK response. It's appreciated."

  • george parkes Jun 04, 2011

    Master cyl. is bad



1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

2000 electraglide, trying to bleed brakes on the rear master cylinder. I take the cap off master cylinder put a hose on bleeder valve, pump up break and hold it down crack the valve and nothing comes out....

does the pedal have pressure then go down after valve is cracked? With a hose on the nipple to a bottle to catch the fluid, press rear brake pedal down. Don\'t pump the brakes. Crack the bleeder valve while continuing to press down on the pedal. Once the pedal reaches the limit of its travel close the valve. Once the valve is closed; and not before; release the pedal and let it return to its at rest position. Repeat this process until you have good pedal without the need to pump, good clean fluid is coming out the valve, and no air is in the fluid coming out the valve. Be sure not to let the fluid in reservoir get too low or you will suck in air and need to start over and don\'t press the pedal too quickly or you can shoot a stream of brake fluid out the reservoir.

In very extreme cases, if you have lost prime in the master cylinder, it may be necessary to bleed the master cylinder first. THIS IS A LAST RESORT. Remove the brake line from the master cylinder. Try to limit the loss of fluid from the brake line to bare minimum. Thread a nipple into the master cylinder. Run a hose from the nipple into the reservoir. Be sure the hose stays submerged in the fluid in the reservoir and pump the brake until no bubbles come out the hose. Remove the nipple and reinstall the brake line. Slowly press down the brake pedal while tightening the line to minimize the air bubble in the brake line. Again be sure not to release the pedal until the line is tight. Then proceed to bleed the brakes as you normally would. Do not pump the brakes up. Just press the pedal down, crack the valve, close the valve, release the pedal, repeat.

Aug 24, 2014 | Cars & Trucks

1 Answer

Bleeding brakes on my 1993 Cadillac Eldorado

This takes 2 people master cylinder is full lid back on . have assistant pump brake pedal 3 times then hold down saying "holding" then you loosen bleeder screw on right rear brake slowly air will come out then a little fluid. tighten screw and say pump it up "holding" as fluid in coming out pedal will sink "Keep pressing" repeat util clean fluid appears. check master fluid level now repeat left rear. fluid level right front fluid level left front fluid level once complte you should have a firm pedal.

May 03, 2014 | Cars & Trucks

2 Answers

What is the problem?

If you step on the brake pedal and hold it down and you feel the pedal going slowly down, that's for sure your Master Cylinder unless you have a brake fluid leak from one of the calipers. If you have a brake fluid leak, you will notice it because you will have to keep on adding fluid to the system. If you notice a change in your RPM when you brake then you may have an air leak from your vacuum to manifold hose.

Apr 03, 2014 | Toyota LiteAce Cars & Trucks

2 Answers

I have replaced my brake pads I've bleed my lines several times. The brakes work fine until I hold the brake pedal down, thats when it slowly goes down to the floor in a few seconds and the brak

sounds like the brake master cylinder seals are worn buy a master cylinder kit and get a mechanic to repair it it is a lot cheaper than replacing the whole unit

Feb 27, 2013 | 1995 Honda Passport

1 Answer

I have installed new rear brake shoes and new wheel cylinders on both sides. I have bled the brakes. Good pedal when engine is pedal at all when engine is started. Bled brakes 4 times.

When engine is running you have a power booster in operation. Without power booster brake pedal will be heavy. With engine running, do NOT press pedal really hard. Just normal firmness. If pedal goes to floor or just too low, it needs bleeding.

Are you sure you did not run the resovior dry?
I would think would not hurt to check the correct procedure for bleeding rear brakes. Here is a YouTube video which should help.

The other possible issue is the master cylinder piston is not sealing well. Might be a good idea to flush it with fresh fluid, but I imagine you have already if you bled it 4 times.

The way I was taught is this. Two persons method. To prevent mess, put a flexible tube over the nipple and drain it to a jar.
Fill resovior with fresh brake fluid. get ready at the bleed nipple with a small closed end wrench, and have helper sit in driver seat. Have helper pump brake pedal (all the way to the floor if it goes there without forcing it) 5 - 8 times, then HOLD PEDAL DOWN. Slowly open the bleed nipple and close it again BEFORE the pedal is released. Helper should keep pressure on as pedal moves down when fluid is released. Repeat until there is no sputtering or bubbles indicating air comming from nipple. Check and fill the tank every couple times to prevent emptying. If it run dry, you have a big problem. You must bleed the whole system at every wheel till ALL air is out.
Hope I have helped.

Jun 22, 2011 | 1999 GMC Yukon

1 Answer

1992 F250 460 cid automatic 2w drive 85000 mi. Just replaced my master cylinder, all 4 brakes, and both front rotors. Afterward I blead the brakes and got bubbles out of fluid. Problem is : when not...

There is never a test or reason to pump your brakes

Accomplishes absolutely nothing.

There is no pressure in a braking system at all,
until you SLOWLY apply the brake pedal.

Then less than 1" off movement in the master cyl,
will develop 600 to 1800 lbs at the wheels

Release the brake pedal, the system goes to zero,

To answer your question

You not suppost to press the pedal hard
The saying goes--you apply the brakes,
not force the pedal arm and pin into the
vacuum booster, as though you want to damage it

When your driving what happens ?
You have higher manifold vacuum and
thus your pedal is normal,why the VACUUM
brake booster

Mar 31, 2011 | 1992 Ford F250

3 Answers

My brake pedal sinks all the way down and won't come to a complete stop unless I pump the breaks. When I'm stopped at a light the brake pedal is fine at first but it will slowly sink down again. I'll pump...

There could be any number of things wrong from air in the lines to a leak of fluid. In any case you need to get the car to a mechanic as it loss of brakes is very dangerous.

Dec 18, 2010 | 1993 Honda Prelude

2 Answers

Dash break light staying on

un plug the module under the master cylinder and see if brake lamp goes out...if light goes out you may have a rear abs problem..hope this helps you!!

Sep 04, 2009 | 1992 Chevrolet K1500

3 Answers

Brake pedal goes down while sitting at light

bad wheel cyclinders, or master cyclinder, possiable fluid leak

Apr 29, 2009 | 1997 GMC Jimmy

2 Answers

1998 chevy s10- brake pedal goes to the floor- just changed master cylinder, brake booster, and bled brake lines- did not help

Ok the BRAKE BOOSTER is ONLY there to give you pwer assisted, otherwise NO POWER BRAKES. ( not anything to do with the low brake pedal ) Hopefully the junkyard master cylinder was in better shape than your original. AS far a bleedinda system, heres what I do. First with a1998 vehicle, I would go to ALL 4 wheels , OPEN & CLOSE slightly each bleeder to insure none of them are FROZEN, and they do freeze shut ENSUE THE MASTER CYLINDER IS FULL and CLOSED Now with an assistant sitting in the drivers seat, ready to pump the brakes, and ABLE TO HEAR YOU. Go to the furthest wheel from the master which would be the R/R. DONT touch anything yet. Tell the asst too slowly pump the brake pedal till it gets hard, and then HOLD THE PEDAL DOWN ( and dont let up on it until the pedal drops. If the ast lets up before the bleeder is closed you **** in air.Repeat at each wheel til the pedal stays hard. Hope this helps

Apr 12, 2009 | 1988 Chevrolet C1500

Not finding what you are looking for?
1995 Buick LeSabre Logo

198 people viewed this question

Ask a Question

Usually answered in minutes!

Top Buick Experts


Level 3 Expert

76846 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22246 Answers

Ronny Bennett Sr.
Ronny Bennett Sr.

Level 3 Expert

6927 Answers

Are you a Buick Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides