Hello all,

Truck - 1955 F250 dana 60 rear, original style front axle with disk brakes
Front brakes - 1995 F250 disk brakes
Rear brakes - 1970 F250
Master cylinder - CPP underfloor power booster

I have no residual pressure valves but this is a stock hight F250 and the master is still above the calipers?

All the front brake components were new/rebuilt: pads, rotors, calipers. For the rear brakes I only replaced the shoes and springs.
I do not have the auto adjusters or parking brake hooked up and the rear brakes are probably not currently adjusted!

Now the truck can stop extremely well, HOWEVER sometimes it does not seem to stop so well for instance when it is raining. If I am going 55mph and I touch the brake pedal lightly the truck will pull HARD to the right and you might get lucky enough to be in the lane to your right.

If it is dry out and I stomp on the brakes hard it will stop fairly straight with maybe a slight pull the left or right?

Why does it pull to the right when it is wet out?

 

Sometimes the rubber lines swell inside causing uneven flow. Are the lines new?

 

Thank you for the reply,

Yes everything was new inlcuding the frubber lines, could have a bad one on there?

I am wondering if added residual pressure valves will change anything?

 

It sounds like one of the front calipers is working easier than the other one . I'm not sure if the residual valves will correct the problem . I built mine without them . Mine are all drum and I replaced everything in the system. I have never had any trouble so far over 1000+ miles. You need to adjust the rear brakes evenly, that might make a slight difference. Also you might rebleed the system in case of some trapped air somewhere.

 

Hey, as far as the brakes go.....

A residual pressure valve maintains a slight pressure (preload) on the brakes so you dont have a soft pedal. This will affect fronts or rears. Not right or left.

Here are some things to check:

Line pressure at each wheel, yes the hoses are new, did you hang the caliper by the hose? did the caliper fall and tug on the hose causing it to internally rupture? Are you 100% sure that hose was fine from the factory? You can swap the left and right hoses to see if the issue follows.

Caliper slide pins, did you completely disassemble the new brakes, clean and lube them? Yes that is a big step, maybe there is a burr that was stuck in the caliper bracket

Proper installation, how long have you had this setup? If it has been like this for a while, maybe the pads will show some sort of wear. Look for uneven pad wear on inner and outboard pads. Look for a tapper in each pad.

Adjust your rear brakes before you even go any further.

Possible faults: bad caliper, hose, improper adjustment, bad line or line blockage. Does one wheel have more brake dust than the other?

Also, check your suspension and steering. When is the last time you have had and alignment. If the front suspension is not adjusted properly, when you brake hard the truck nose dives and can cause a pull.

 

Thank you for the response!

I was thinking the redidual pressure valves may help if somehow one line is holding pressure on the caliper and the other is not, maybe the passenger side hose is bad.

I did not damage it, or at least I don't remember doing anything. I have had this setup for about a year and it only pulls hard to the right when it is really wet out at higher speeds.

(Although sometimes at stop signs I feel that only the front right wheel locks up if I stop too hard)

I had cleaned and inspected everything when I installed it but that does not mean something bad has not happened under there since then, I would think if the slider pin is jaming that would not nesecsarily cause that one wheel to stop harder would it?

I will certainly check the pads on both sides to see if there is any weird wear?

I would like to fix/make the front braking even before bringing the rears into play as they just mask the issue when I adjust them! Does that make sense?

As for the steering it is fairly good, when dry the truck will pull a little to whichever direction you bias the wheel a little, front right probably still is stopping harder.

Thanks again, I will take pictures when it comes apart.

 

I spent almost a decade as an ASE master tech and currently work on durability testing for a manufacturer so take this at a bit more than face value.

My personal and professional opinion/where I would start:
1: Take the truck for a test drive, stop in a safe manner where the truck will duplicate the hard pull. Get it to duplicate a couple times and immediately Get out and check each rotor temperature. Is one way hotter than the other? Or is one warm and the other cool/cold to the touch?
2: Adjust the rear brakes.
3: jack the front end up and support both sides with a jack stand. Check the turning force for each wheel, is one harder to turn than another?
4: Check/inspect the suspension and bolts for proper free play and bolt torque.
5: Remove both front wheels and visually inspect the brakes.
6: take pictures and measurements of pads etc.
7: Remove the caliper and depress the piston fully into the caliper, is it tougher on one caliper than another? is the piston rusted in the caliper? Can you depress that caliper? If you cant, open that bleeder screw and then attempt to depress the piston (this will help diag a bad hose)
8: Look at the sliders and slider seals. If there is a seal that is torn or rust/debris is in the caliper mounting bracket, it WILL cause a delayed caliper operation and CAN cause a pull. The caliper might be doing its job but might be doing it at the wrong time and causing a pull.
9: assemble. Torque everything to spec, use proper lubrication.
10: pump the brake pedal to achieve proper brake preload and then test drive.
11: If you havent been to an alignment shop in a while, I would go get it professionally aligned. This will rule out any oddball results.
12: test drive and report back here.