Hi Guys.. I've been trying to solve a problem with my Drum-Brakes, since I bought the car 1 year ago.. Problem: The car "vibrates/shakes" severly if I apply the brake normally What I've done in order to fix it: Brand new Drums and wheel cyllinders in front ,and new brake shoes.. Brand new brakes shoes and cylinders in the rear, and I've had the rear drums checked, and their okay ( not out of round) BUT, Front drums HAVE NO balancing weights, and rear have the old weights ( probably from when the car was new) So.. Is the balancing weights causing this problem? or maybe a dirty distribution block?? Could wheel-bearings be causing this problem? And yeah , the brakes have been bled, and the pedal seems fine.. ANY HELP or POINTERS would be gratefully appreciated, as I'm kinda stuck, and considering a Disk-brake Conversion unless i figure this problem out. Sturla
Can you tell if the vibration is coming from the front or rear? Or is the whole car shaking. Do you feel it more in the seat, steering wheel or back through the brake pedal? Does it pull one way or the other while braking? Are there any abnormal noises while driving (not braking) or accelerating? Has there been any modifications to the suspension or drivetrain or is everything original? It sounds like you have eliminated likely possibilities with the brakes themsleves. Considering all the work you did and the symptoms did not change, the problem could be elsewhere such as rear axle control arm bushings, transmission or driveshaft center bearing mount. The only shaking-while-braking problem I've had (not on a Riv)turned out to be out of round rear drums. It was a tough problem to diagnose because its fairly uncommon. You might want to have the rear drums trued up to be 100%sure. If wheel bearings were bad enough to cause shaking while braking you'd be able to tell by raising the car and trying to push/pull on the tire checking for movement. Or they would be making noise while driving. The weights on the drums balance the drum much like a tire is balanced. If that was a problem you would notice that more while driving at higher speeds and not while braking. Just throwing some things out here to stimulate other ideas.
New drums are often out-of-round right out of the box. Have the new drums turned. Been there, done that.
Hi Again.. First of all, the car has been lowered 2 " all the way (front and rear) with custom made springs ( some company in Kansas made them) This spring I had the entire driveshaft out of the car, replacing the rear CV joint.. at that time the center driveshaft bearing mount looked fine and was re-used.. Looking at the MOT-checks the previous owner had on the car ( and old retired couple) I see that the local garage has at 2 separate occasions commented on "loose/ not tight enough " wheelbearings.. As for shaking , it's pretty much the entire car.., maybe more in the front of the car.. As for "where" i feel the vibration, the entire instrumentpanel cluster rattles along with the front Transmission seem fine and all that.. No noises, and no "pulling" that I'm aware of, though i must admit that 255x50x17 wheels pull the car fromt side to side on uneven tarmac..
Okay, will have my front drums checked ( even though they're brand new) I forgot to mention that the car has rear adjustable Koni Shocks ( fitted when i bought the car) Could this also be a front-end/link issue ?
If you want to isolate the front or rear drums as the problem, try applying the brakes with the parking brake pedal. If the car shakes, the rears are at fault. If it doesnt, then look to the fronts. Naturally, do this on an empty road or in a large parking lot. And make sure you have your hand on the release.
I have run into this problem many times with our BIG Buicks. Try changing the hold-down & return springs with heavy duty ones. If I remember correctly the ones from the same/similar years Cads will work.
Update.. ! I tried pulling the Park Brake pedal while driving, and no shaking/vibration.. So, I guess the "problem area" is the front end of the car.. Vibrations are felt mostly via the steering wheel,and just by looking at the hood while braking, I can see the entire front of the car shaking when I push the brake pedal.. I also have "some vibrations" and shaking at higher speed ( around 80-100) So besides the Front Drums, what else is there to check ( or could cause that type of vibration issue?) I tried replacing the Return springs on both sides of the Drum brakes (front), with new ones (upper return springs) with no difference in behaviour..
Have it put up on an alignment rack and checked out. Some shops will check it out and not charge you for the alignment but give you and est of what needs replaced. then you can take it from there.
What would happen if I testdrove the car in a large parking lot WITHOUT the FRONT drums..... That would tell me if the drums are causing the vibration?
That would be ugly.....Besides the wheel cylinders literally exploding and brake fluid going everywhere. Really bad idea. Take the front drums off and bring them to a machine shop. Tell them to check the runout. If it exceeds .005 they need to be resurfaced to bring them back in trueness. If they exceed the "machine to" measurement, they will need to be replaced
Ok then, I guess I won't try that then.. Drum Brakes are a thing of the past for me.. As for the front drums, as I mentioned earlier, they're brand new. Kinda irritating that one buys a product that needs "fixing" when you think you're buying a 100 % operational product..
How are the tires? I've had vibration problems in the past and it turned out one the tires was starting to separate in the plys. It was not an easy problem to spot as the tire looked perfect and was not out of round.
Hi.. Tires are brand new, and I had the same problem with the old ones (Tyres).. But I guess having the new front drums checked,along with the entire front end of the car is the best plan,, and along with the hold down springs
