steering problems

[gafiredog]

I need some help with this, My 1987 crewcab dually was used before I got it to haul cars on a hotshot 5th wheel trailer. the steering was shot, along with the brakes. my problem is, every time I hit the brakes it jerks left or right every time, especially if i hit the brakes hard. I have replaced everything in the frontend except the ball joints, and the steering box itself. I have installed new brake pads, and calipers. and put on new tires. I even installed a steering damper. it still does it. any ideas on the problem ?

[Keith Seymore]

2wd or 4wd?

How does it drive going straight down the road when not hitting the brakes? (Pretty stable? vs hard to handle?)

K

[hartbraker]

I would suggest bleeding the front brake on the opposite caliper from the direction the truck pulls when stopping. I would guess, from your description, that the calipers are not braking evenly.

[Jonboy]

I would check the front brake hoses. They are prone to failing internally, causing the brake fluid to be cut off to that caliper.

[86c20]

if it is going both ways i dont see it being the brakes if its as bad as he says. but if it is not wondering down the road then it could be flex lines. did you check the ball joints the right way? loaded and unloaded.

[bilfman]

As above stated make sure the other side is bled properly. Another problem that I have come across is the caliper can bind when perssure is applied so on the initial push of the brake it stays on hard and does not release itself. So to fix this make sure the track that the caliper travels is clean and free of debris.

An easy to check this problem is jack up the pulling front side, turn the tire before hitting the brakes, this is to get a baseline for how hard it is to spin the tire. Then apply the brakes, get out of the cab and try to spin the wheel. If it is hard to turn the the caliper is binding and not releasing. If it is tougher to turn the caliper is binding somehow. Ususually some good wire brushing and cleaning will be enough to help clearances for caliper travel.

[gafiredog]

the truck drives straight, and there are no problems with handling. only when the brakes are applied does it pull, either way left or right, there is no pattern to it either, one time it will pull left, the the next time it may pull right. its 2 wheel drive, and I didnot replace the hoses going to the calipers. I didnot check the ball joints, is it possible they may cause it to pull when the brakes are applied ? seems like it would steer, and drive bad if the ball joints were bad, also the tires are wearing good,no excessive wear on the sides or flat spots. if that helps. I'm out of ideas.

[durty harry]

Originally Posted by hartbraker

i would suggest bleeding the front brake on the opposite caliper from the direction the truck pulls when stopping. I would guess, from your description, that the calipers are not braking evenly.

x2

[Keith Seymore]

Agree - if it goes down the road good normally and just gets squirrelly when you hit the brakes - then it's time to focus on brakes.

Check or replace those front hoses, as has been suggested, and double check anything related to calipers - do they slide freely on the knuckle? Are the pistons getting hung up in the bore? Is the friction material wearing (or breaking in) evenly? etc.

Pistons in the bore have been a big problem for this style caliper but it usually causes a problem on one side and stays with that side. The truck goes the opposite direction of the bad caliper because the bad side is not doing it's fair share. Make sure the piston bore is smooth (no screw thread type machine marks) and make sure the leading edge of the piston is free from burrs or roughness (next to the groove where the dust boot seals).

K

[gafiredog]

Originally Posted by Keith Seymore

Agree - if it goes down the road good normally and just gets squirrelly when you hit the brakes - then it's time to focus on brakes.

Check or replace those front hoses, as has been suggested, and double check anything related to calipers - do they slide freely on the knuckle? Are the pistons getting hung up in the bore? Is the friction material wearing (or breaking in) evenly? etc.

Pistons in the bore have been a big problem for this style caliper but it usually causes a problem on one side and stays with that side. The truck goes the opposite direction of the bad caliper because the bad side is not doing it's fair share. Make sure the piston bore is smooth (no screw thread type machine marks) and make sure the leading edge of the piston is free from burrs or roughness (next to the groove where the dust boot seals).

K

thanks for the help guys.