I need some help with a 72 cutlass that pulls left when the brakes are applied. I have tried many things to correct this. It started with a 4 wheel drum car pulling left with new brakes when I bought it. I have replaced the drum brakes with rotors / calipers, porporting valve from a 72 donor car, new right caliper, new rubber brake lines, new master cyclinder, New metal line left front and rear brake lines. Brakes have been bled with good flow to all wheels. New tires, front end alignment have been added. Simply what am I missing a bunch of new parts with the same problem. Shocks appear to be on the weak side.

 

Forgot to mention that the upper and lower ball joints were also replaced when I converted to the disc brakes.

 

So, you replaced the left front brake line only? I would check the right side to see if it is not pinched or possibly is partially blocked. Seems like the pressure on the right is lower than the left. Yes, it's the one that goes under the engine and around. Probably why you didn't replace it.

 

I replaced the left front and back line as they would not come unscrewed when I replaced the porportion valve. Right line did come loose and I agree that is all that is left. Will probably replace it tomorrow although it seems to have a good flow when bleeding and changing the caliper. Thanks for the reply.

 

Ok I have now replaced the last brake line and the problem remains. Any other ideas? Thanks

 

It could also be related to your rears. Check the adjustment there also.

 

I have this same problem on my 70 supreme. It was happening before and after front end rebuild. I still have drums all around.

 

I have new shoes and springs on the rear that seem to be adjusted properly. (I have checked them several times) The brake lines to the rear have been replaced

 

Well you sure have been methodical in your approach. I'd be looking at a few things:

1. The donor proportioning valve could be malfunctioning
2. The new right caliper may be defective and the piston not driving out properly.
3. Conversely you may have a problem with the left front caliper. Did you rebuild it when you got it? A rebuild kit is really cheap and it only takes about 20 minutes to do.

You did clean and lube the caliper bolts, or replace them with new ones when you changed over?

 

Thanks for your reply. I drove the donor car before I stripped it and the brakes worked fine. What really has me puzzled is this car pulled left with drum brakes before I made the change over. (I honestly expeded the change over would fix the pulling problem). I am helping my 15 year old for his first car. We have cleaned everything very well. I don't think The old caliper on the right side was bad, but I changed it two days ago because am running out of things to try. I have not changed the left side, but it spins freely and drives straight as an arrow. I am honestly stumped and figure I am over looking small, but just can not figure this one out.

 

This is kind of like a Sherlock Holmes adage: If the donor car drove fine and braked fine, the braking system is not at fault. Your car (drums) did not drive/brake well so IT must be the one at fault.

If it was my car, I'd start by jacking up the front and have your son apply the brakes while you see if either wheel will turn. If one wheel turns, there's got to be something in either the master cylinder feed, or the brake hose that's keeping the caliper from generating pressure. If the braking system works fine on test, it's something else with the car......

Was this car ever in a front end collision and the frame not straightened properly??

 

maybe its not the brakes...could something be broken or weakened and when applying the brakes allows that part ot deflectand car pulls to one side ?....Im just spitballing here maybe CA bushings or CA mounting bolts one broken but still in place ??

 

I agree, or maybe just rubber bushings that are more deteriorated / damaged on one side than the other.

See if you can remove the wheels and find a place to stick a length of pipe to pull each wheel straight backward - if one wheel pulls father, or is easier to pull (presumably the wheel on the side that the car pulls toward when braking), then look at all bushings very carefully.

- Eric

 

The only other thing I can think of is the hard lines that feed the front.

 

Good ideas. I have tried several already, but will check again this weekend. We bought the car this spring and the frame appears to be in good shape, All the hard lines and rubber lines in the front have been replace (one or two at the time to troubleshoot). All 4 wheels turn freely when jacked up, if the brakes are applied they all stop. I will try the pipe idea and see if any thing is giving and report back. Thanks for all the input.

 

If it is the upper/lower bushings? The lower ones aren't terrible to do once you get the springs out. The upper bushings though are a real PITA because of the cross shaft bolts - especially on the drivers side. IF you need to replace them (and on an old car like this it's probably a good idea) you might want to take out the steering intermediate shaft first so it's easier to access those bolts.

Hope you find the solution somewhere in the suspension as the others have suggested it may be.

 

Ok think I have finally figured this one out. Brakes were checked out ok, but I had failed to check the lower control arm bushings. In a 40 plus year old car simple to say they need to be changed. Working on it now. Thank you all for the input.

 

whohooo what do i win ???

glad you got it figured out

 

Check/replace your wheel bearings. I had one just like this for about a year. Finally on a trip the bearing when up. I found a deaerl open in central PA and the owner was working on a friends car and opened the parts department for me. I replaced them in the side lot and it fixed my brake pull. The bad bearing was heating up the rotor causing it not to work as well as the other one. I was stumped for a year.

 

Glad you got it figured out. Way to go Retro Ranger - you nailed it. You win an opportunity to help this guy change out his front suspension!!! Fun stuff.

Those bushings must be horribly worn or ready to fall apart

 

Mine goes into a full right hand drift after locking them up after my front disc conversion . Need to back off rear drum I believe.