Hello everyone,
new to the forum.
I have a 98 Lesabre Limited with ABS I am passing along to my 19 year old son.
The car sat for a while (around 6-8 months) while he was getting his license and saving up money.

We took it for a test drive the other day and heard a loud whine coming from the front wheel and narrowed it down to the bearings.
We replaced both bearings, no more noise.

But... There is always a but, we lost brake pressure. Pedal goes to the floor.

We bled the brakes, same thing.
Replaced the Master cylinder, bench bled, then bled the brakes farthest to nearest several times, still no pressure. Also replaced the seal of the check valve, still no pressure. Pedal releases/returns when is pressed and let go so I am not sure if it is the booster. I inspected hoses, etc. no leaks anywhere.
Short of replacing the booster, I am out of ideas.

Any suggestions, Ideas? Would be greatly appreciated.

Mike

Replace the flexible brake hoses to the calipers. I had an issue with my 93 and my sister with the 98 where these hoses deteriorate on the inside and produces "flaps" that interfere with the flow of the brake fluid. No way to be sure if this is the same with your car or not; no way to look inside of the hoses without cutting them apart. Not expensive to replace them and it may help; certainly would not hurt anything as these hoses do weaken over time.

And to replace the hubs you had to take the calipers off and hang them etc. The hoses are not expensive so give it a try and see.

Does sound like a bad master cylinder. On some vehicles you have to follow a specific bleeding pattern; did you find this for the 98 LeSabre? A bad booster would not prevent you from having brakes, it just helps in making it easier to press the brake pedal.

Thank you Kimberly,
I didn't think about the brake hoses. The car was sitting for a while, so deterioration is certainly a possibility. The brakes were bled, but I didn't find any specific pattern online that I needed to follow.
And just to be clear, I do have brakes but I have to push the pedal almost to the floor to get the vehicle to stop. But it does stop. It just seems like there is no assistance.

Mike

Dose it seem if the brakes are stopping the car evenly; no indication that some wheels may be applying the brake more than other wheels? You can test by stopping; in a safe place of course, with your hand off the wheel and hitting the brakes and see if the car is being push to one side or not.

In my case the hose prevented the release of the caliper so the brake was being applied constantly on the passenger front wheel. However, the opposite can happen in that not enough fluid pressure to push the pads against the rotor. However, it would be odd for both sides to do it at the same time; hence uneven braking I mentioned.

By the way, for the rear; which are drums; the shoes may need to be adjusted out; the self adjustors don't always work. If the rear shoes are too far from the drum; you won't get proper pedal height. Now the best way is to take the drums off and inspect the shoes for excessive wear. The drums will develop the ridge that makes removal hard; a brake spoon is used to try and turn the adjust back in. Take photos of the rear brakes or do one side at a time as it can be confusing how things go back if you need to replace the shoes. I need to inspect my rear brakes; I have new rear piston sets so instead of honing etc, I am just going to unbolt and replace the whole unit. Check on RockAuto.

I have seen bad wheel cylinders cause this some time with no sighs of lost fluid.

Thanks for all the replies guys. Turns out it was the brake line (from the master cylinder) It was sucking in air. Ordered a set, should arrive today. I'll let you know if that fixed the issue.

Mike

Brake lines do not suck in air, they leak, and you should have seen a leak.