O.T. Buick brake system

IA Roy

Well-known Member
I bought a low mileage (102K)2006 Buick Lucerne the other night. Very nice car. It has been sitting at least the last 4 months. The owner is in a nursing home and his son sold it to me. He said it had a recent brake job before parking it. I have no reason to doubt him. I drove it about 70 miles counting test drive and trip home. I did hit the brakes pretty hard before one corner. Everything worked as it should until I got about 2miles from home. Then I got a real soft brake pedal. after a couple more stops, I didn't have any brakes. I checked it yesterday. Reservoir was empty. I went down into the grease pit to check for caliper leaks. (First time down there since I walked into it and broke my foot the end of August). No apparent leaks at any of the calipers or lines leading to them. I refilled the reservoir and tried pumping them up. Did not get any resistance after 30 to 40 pumps. I haven't looked too hard to find where the fluid went! Is it possible that the master cylinder and or vacuum booster failed and the fluid got sucked through the engine? I will try harder tomorrow to find a leak. Thanks for taking the time to read this. I will post results when I find out what happened. Roy
 
Does your Buick have the big plastic pan under the engine? If its like the Cadillacs, all the brake lines wrap around in front of the engine and down the right side of the car to go to the rear. If you blew a line on top of that pan, it could hold a bit of brake fluid before it starts running out or just drip somewhere you wouldn't expect.. I just did the lines on my 05 DTS not too long ago. It blew one up front. I did them all. If one is rotten, the others probably aren't too far behind.
 
Might not apply to such a new vehicle, but look up under the dash where the master cylinder actuator rod comes in thru the firewall.
I have had a couple where the cups or seal blew out, ripped or whatever and the fluid leaked out down the inside side of the firewall and soaked into the insulation under the carpet.
 
You can loosen the master cyl from the booster and pull it forward enough to check for leaks. I would think even with a master cylinder leak the pedal should pump up enough to feel resistance, unless a lot of air got drawn into the lines when low.
 
You are leaking fluid somewhere. If the calipers or the brake lines are not the culprit I would put my money on the master cylinder.
 
I hate it when this happens. AND IT HAPPENS A LOT. ( ok so much for my rant, sorry) Several people commented, and gave good advice on his brake problem, but NOBODY actually answered his question. I am no brake expert, but as far as I know, there is no way for the brake fluid to get in to your engine. Greg
 
Actually its pretty easy. The master cylinder starts to leak into the diaphragm of vacuum booster. Eventually brake fluid soaked diaphragm starts to leak and the engine sucks the brake fluid into the intake with the vacuum lines. This seemed to happen a lot with old grain trucks (notorious for lousy brakes) and other older neglected vehicles. I doubt it would be an issue with a fairly new car.
 
(quoted from post at 07:35:48 12/05/18) Actually its pretty easy. The master cylinder starts to leak into the diaphragm of vacuum booster. Eventually brake fluid soaked diaphragm starts to leak and the engine sucks the brake fluid into the intake with the vacuum lines. This seemed to happen a lot with old grain trucks (notorious for lousy brakes) and other older neglected vehicles. I doubt it would be an issue with a fairly new car.

Yes. That is exactly how it happens.

As far as answering the Buick question, brake systems are not simple anymore. Anti-lock systems and whatever just makes it very complex. It isn't a do-it-yourself project anymore. Take the car to a professional.
 
Wasn't there a similar post to this with the same issue sometime in the last couple of weeks? Same problem I think but I can't remember what kind of vehicle, maybe an older truck?
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top