Hello all, got an interesting problem, and just wanted to solicit opinions on this one.

My Superduty has been pulling to the left when I hit the brakes for a few months now. In the past it's done it, like within a year or two after buying it brand-new off the lot, but that was because one brake pad had rusted itself to the bracket and was not doing a darn thing. Once or twice more, it was a stuck caliper pin, which was quite obvious when working on it.

Last year, around August, I replaced the rotors and pads with Advanced Auto parts stuff. Rotors are still great, pads look brand-new, and it wasn't pulling up until the past month or two.

But this most recent pulling has been a problem that I can't find. It's not the pins, it's not the pads, and now I find out, it wasn't the calipers

This past weekend I went so far as to replace the calipers with Napa rebuilt "semi-loaded" calipers (all hardware and pins and bracket, except for the pads) and pressure-bleed the entire system. The old fluid was green, not black, but now that it's been bled, the pedal is a bit firmer than it was.

I wasn't going to replace the calipers without checking them first, but I broke both bleed nipples off and I wasn't about to wrestle with an easy-out and try to get the darn things out. For $70 per side, rebuilt caliper with hardware and bracket, can't go wrong. (Checking the calipers would have involved using a C-clamp to compress the caliper slightly, then backing off the C-clamp - if the pistons come back out a slight degree, they are free and the seals are still "grabby" and resilient).

While bleeding it, I saw a piece of black crud (rubber?) about 2-3mm in size come out of the left side. Didn't think much of it, figured it was just built up crud from somewhere.

Today, the first commute after doing the calipers and bleeding, it's still pulling just like it was before the calipers. However, I did notice at one point when I hit them, they pulled like they normally do, but seemed to go straight a few seconds into it. It does seem that if I keep my foot on the brake, the pulling is much less after the initial second or two, but if I stab them again, it pulls like crazy.

And by "pull" I mean the steering wheel actually moves in my hand. So with that in mind, it's actually a front-brake problem. If it was the rears, the wheel wouldn't pull like it does, and if it was something loose in the suspension, I would have found it already after checking everything, and it again, wouldn't pull the steering wheel like that.

Now, given that black piece of whatever that came out of the left side, I'm beginning to wonder... if it was rubber from the inside of the hose.

Is the right brake hose causing the pulling because it's coming apart just like the left one might be?

I've gone over and over this in my head this morning, and thought about the ABS unit possibly dumping pressure from the right because of a leaky valve (see side note below), but I would think that once the pedal stab was over, it would even out and not pull at all.

However, this thing pulls left quite a bit, even after the pedal has been held down for quite some time. Usually. Sometimes, it subsides and doesn't pull. But mostly it does no matter what I do, keep pressure on the pedal, let up and reapply, whatever.

Does this really sound like a bad hose? It's intermittent, but usually pulls like 90% of the time.


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Side note: The ABS unit in my truck, and most Fords of the time (not sure about later than 2004 or so) is a Kelsey-Hayes three-channel unit like this:

Kelsey-Hayes RWAL Antilock Brakes

It's the same system found in Chevy Suburbans and light-trucks, which I have worked on before and know a bit about.

In my case, it can't be a dump valve leaking, because it would effect pedal-height and not PULL to one side like it does. The only way that could happen is if the isolation valve was closed, AND the dump valve were leaking at the same time.

I haven't, however, gotten the ABS to activate just to see if it changes anything. On my way home tonight I will see if I can find some dirt or sand and get it going

 

Probably a collapsed or restricted rubber front brake hose. The right front one is probably the culprit, but I'd replace both of them.

When you were bleeding them, did you notice any difference in the flow rate of the fluid?

 

I had an F-150 that started pulling to the right when braking. I looked at everything I could to find out why, but all the braking components looked good to me. I finally threw in the towel and took it to a mechanic for a brake inspection. The mechanic called me a few hours later and stated my brakes were fine.............but..........if I brought the truck in because of the pull to the right while braking he fixed it. When I asked how, he said I had "radial pull" which caused a pull to the right while braking and it was fixed by rotating the tires from front to rear. If the offending tire is on the front axle it causes a pull to that side while braking, but not on the back axle.

As I thought back, the pull did start when I rotated the tired myself.

 

OK, a few things to report:

1) Changed right brake hose, and the problem is GONE. Now it pulls to the right slightly once in a while - I have a new hose for the left side, so that's going on this weekend.

2) Rotated tires at the same time I did the calipers because they needed it. And it still pulled afterward.

3) Did not notice any difference in flow rate when bleeding. I used 15 lbs on my home-made pressure-bleeder (see below), and it flowed well.

After all this, I am going to cut open that brake hose and see what's up with it. I did notice a piece of black "something" in the hose I was using to bleed the right side last night. I will investigate that further as well.

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Pressure-bleeder. I bought a master cylinder cap and rubber seal from Napa, at around $8 EACH (yes, total of $16 just to get a new master cylinder cap with the rubber gasket).

I used a "bulkhead" fuel fitting meant for a boat, I think it was a 3/8" nipple on each end, with a nut and thread on it so it could be used to pass fuel through a bulkhead (wall). I cut one nipple off, the one opposite the threaded side. It came with a nut and two flat washers.

Drilled a hole in the new master cylinder cap, just enough to be able to thread the bulkhead fitting through, cut a hole in the seal, JB welded it between the gasket and the cap right around the hole, put some under the washers, and around the nut on the top of the cap to strengthen it. Let cure overnight.

I had an air-chuck mated to a 3/8" nipple from another project, so a piece of 3/8" fuel hose between the cap and the air chuck, and I was good to go.

I put a light coating of grease on the nipple at the cap, and used hose clamps on each end. The grease is so that the cap nipple can rotate inside the hose, which is handy when installing and removing the bleeder cap so it can be turned without having the hose flopping all over the place.

Used that with 15 lbs of air to pressure-bleed the system. Worked GREAT.

I was going to use a small sprayer to make the pressure, and fill it with brake fluid so it would automatically refill the master with fresh fluid without having to refill by hand, just like the professional ones do. But ... if the custom-made cap or anything else leaked air, it would overflow the master cylinder reservoir and I wouldn't be near it to release the pressure.

So, I just used the good old air compressor that I have a regulator on, set to 15PSI, and make sure the master cylinder reservoir was full each time I bleed a caliper.

If you do not have a regulator, DO NOT DO THIS - 100psi+ is too much. And make sure your air supply is dry.

Keep an eye on the master cylinder level while bleeding. I found that I could FLUSH the entire right side front caliper and lines and I was only down about 1/4th the way on the reservoir. I refilled after each caliper just to be on the safe side.

I could probably have run up to 30PSI or so, but I didn't feel it was necessary. I got a good flow at 15PSI out the bleeders, and it was easy to control.

After almost 30 years of playing with vehicles, this was my first time with a pressure-bleeder, and WOW - what was I waiting for? I was able to flush the entire brake system in about 15 minutes, after the wheels were all off, that is...

To anyone listening, I highly suggest this method...

 

I have the same brake problem you are having. I to have had it for a long time. Replaced on caliper and the slide pins on both, plus the brackets cause I couldnt get the pins out of one, so I did both at the same time. The problem always goes away for a while. Now its back again. My buddy just did the exhaust manifold bolts and the brakes were miracuosly fixed again (he didnt touch them) Now after 3 weeks its back again. I think I'm gonna get new brake lines since they are original. and try that. I will report back when I do it (might be this weekend)

 

That's kinda why I made this thread in the first place. If anyone is having issues like I did, that this thread would get you thinking about the brake hoses.

Now, since that one was bad, I'm of course doing the opposite side this weekend.

I guess it's time to do the rear one too...

 

Great thread. going through this exact same thing on an 03 super duty right now.

All new hardware up front, wheel jerks hard left when you touch the pedal.

Thanks for putting this up.

 

This is an interesting thread and may have some relevance to my problem, in this thread: "Front brakes not working 100%"
I had not really thought about a hose issue.

Thanks!

Tom

 

A thousand thanks to you for posting this. I was ready to check what accidents my insurance covers until I read your post. Swapped front tires side to side and it pulled the other way.

At least it has all new brakes, rotors, calipers and hoses on the front.

 

A bound-up front outer U-joint can cause this. How many miles on the truck? Ever had the front outer axle U-joints or ball joints serviced?

 

Not sure if you were replying to me but if so, it was the tire. That's why it pulled to the other side when I swapped front tires.

 

Yes, and I was adding info to the thread for others when they do a search on the subject.

 

Gotcha! the interwebs are good for helping spread information, not just ****.

 

I usually replace those hoses every 2nd or 3rd brake job.