Braking Pulling to Right

[70rr-brian]

OK, so I have had this issue for 3 years with the RR and have monkeyed with it only once and just never went back to it until today.

The car pulls to the right under braking. Not like OMFG I'm changing lanes uncontrollably but enough to be noticable and requires correction.

1- Replaced all front end components 2 years ago. Tie rods/ball joints/control arm bushing, all bushings etc. The car drive straight as an arrow down the road at any speed.

2- The tire pressure is the same in both front tires. They are the same tires and no uneven wear on them with 8k miles on the car since front end replacement.

3- The brake shoes on the car were brand new when I bought it. They still look brand new for that matter. No uneven wear on any of the shoes.

4-The previous owner put all new brake hoses on the car.

5- The drum surfaces look perfect and are perfectly round.

6- The wheel cylinders do not leak or stick.

7- The brakes have been bled with no change.

8- The self adjusters are connected and behaving as they should.

9- The tension on the wheels when free spinning is the same on each wheel.

So today I decided to monkey with it and do some testing. I did several things but the most telling thing was I loosened/brought in the right shoes a LOT with the adjuster just to see what would happen. When I did that the car now yanks to the left upon inital braking then pulls back to the right.

I am thinking the left wheel cylinder is either not maintaining pressure (although not leaking) or has a different wheel cylinder bore diameter than the right side. The wheel cylinders do not look new but don't look original either. Or the new hoses the previous owner put on are collapsing internally on the left side.

Does this seem like an accurate diagnosis? If not, I am open to advice. I just hate throwing parts at it if I can avoid it.

Thanks,
Brian

 

[flypaper]

i think you are on the right track
from what you say
i would be suspecting either the wheel cyl like you think or a defective brake hose.
the one thing i would do before condeming a wheel cyl
is have someone else step on the brakes a few times
and watch the left brake hose very closely for swelling, not collapsing
i've seen them be garbage right out of the box before.

 

[Revhendo]

What about the brake return springs? Used to be, if you dropped one on the ground and it went "thud" and not "ping", it was bad......

 

[flypaper]

What about the brake return springs? Used to be, if you dropped one on the ground and it went "thud" and not "ping", it was bad......

that would cause a sticking or dragging/not releasing wheel problem
and it would pull to one side all of the time or after the brakes are applied.
not on the application like he says its doing.

his problem is the left side is not grabbing properly and
most if not all of the time it is from losing pressure somewhere.
wheel cyl/bad hose,leaky lines are usually the culprit
he should also look over the left side really good for leaks also.

 

[Revhendo]

that would cause a sticking or dragging/not releasing wheel problem
and it would pull to one side all of the time or after the brakes are applied.
not on the application like he says its doing.

Not entirely correct. If the springs are weak, yes, you could have a non-releasing brake assembly. You also may experience faster application of the brake assembly. Remember, these are duo-servo self energizing drum brakes. Residual pressure is only in the 10psi range and it doesn't take much spring tension to overcome that. Hence the reason most backyard mechs get away with never changing the hardware.

his problem is the left side is not grabbing properly and
most if not all of the time it is from losing pressure somewhere.
wheel cyl/bad hose,leaky lines are usually the culprit
he should also look over the left side really good for leaks also.

Most likely the problem.
Other things to consider are the actual hard lines being corroded and clogged. Partial restriction could cause the wheel to lock by allowing pressure to build after several applications. Full restriction could cause the brake not to apply at all. Which most likely is not the case as indicated by his latest adjustment test.

Other things to check would be,
Drum over turned beyond limit.
Double check the condition of the rear brakes.
Check to make sure they are the correct shoes for the vehicle.
Check the actual bore size of the wheel cylinders. (It's embossed on the inside of the cup).

 

[74Satellite]

all of the above are great ideas to start looking. I would also carefully inspect the entire left side hard brake lines. Look for kinks in the line which would allow possible build up and restriction of fluid. Really insect the actual brake hose for swelling and collapsing, and of course cracking.

Only way to know if the inside bore of the wheel cylinder is different is to pull them off and measure(Preferably with a caliper).

I am also assuming that all 4 tires are the same size, even having a sigle 215 versus three 225's can make a big difference.

 

[Cranky]

Also, check the drum width to make sure they are both the same. If the shoes are the same width, the width of the drum doesn't make much difference. I've heard of cars coming from the factory with different size drums\shoes on the front....also, different diameters. If all that is good and the cylinders are too, then I'd be looking at the hard and soft lines like what has been mentioned. Another problem with the soft lines is if they were made in China or not. We get a lot of crap from China and that just compounds problems.

 

[Meep-Meep]

This could very well be a strut rod bushing issue. You did say you replaced everything in the front end but might be worth a look anyway.

 

[flypaper]

you are correct rev
my memory is fading fast in my old age... lol
i was also sort of assuming (my bad) everything was new
including the brake hardware
but as you said, many will think they are saving something
by not replacing
then it will end up costing them more down the road.

 

[Big Jim]

Might also check the mounting bushing in the lower control arm-(where it attaches to the k-member) we all know how I found this one...