You may have the right side adjusted to close. When they warm up they may expand a bit and thus become closer so when you hit the brakes that side grabs. Jack it up and turn the adjuster back 6 clicks or so and see if that helps.
I understand what you're saying, but maybe I'm not being clear: if this eccentric adjustment was at fault, why would it only pull SOMETIMES?
Replace your flexible hoses. I have had bran New junk internally collapse. Find a small hill and hit the brakes hard locking up the wheel and wait within a hour the thing will release. It is one of those. Things that will get worse. Changing out hoses won't take more then a few hours, mason jar, and vacume line, to do yourself. The amount of rust will determine how easy it goes.
Check the left front drum after you drive it I'll bet hot. Hot brakes don't have as much friction coefficienty as cold IE brake fade. Somethings holding the brake on a little bit brake adjusted a little to tight or a bad hose not letting it fully release.
also don't overlook the wheel bearings, one with some play will allow the drum to slightly cock to the top and cause a bind up. my dad had one that pulled to the right when cold and after driving a bit was ok we tried everything and gave up. finally a few years later he took it to a garage and had the front end rebuilt and the brake shoes changed and maybe something else brake related it solved the problem. never knew what caused it. the guy said all he did to the brakes was change the shoes.
Post #35, good idea to check the bearing adjustment. With drum brakes, I always liked to keep the 2 drum diameters as close as possible when I cut them. With the pull is it steady or does it feel more jerky? Which may indicate something on the linings. This could be heat-activated and not show up until they get hot.
The pull feels pretty steady with moderate pressure on the pedal, but if you jump on them pretty hard, it seems to grab initially, then steady from there
New parts don't mean good parts! Had a similar situation on the front drums on my 58 Fairlane. No brake pull when slowing down, but it would pull pretty hard when stopping. After much frustration, I pulled the boot back on one of my "New" wheel cylinders and found brake fluid seeping out.
I still think it is your flexible lines. But, I have had the same thing on a rear axle that turned out to be a bent piston inside the drumb that once pushed far enough would not return. I bet if you find a hill then hit the brakes hard a few times that front line will collapse acting line a line lock. Sit in the thing and after a hour of just sitting that break will release. That's the line, If it does not release that's the piston and hitting the brakes real fast will pulse the fluid and free it up.
Just a note on bleeding brakes, for all you guys without helpers (me). An old timer showed me a trick one time, and I was as skeptical as all you will be when you hear it, but trust me, it works. The guy ran a brake and alignment shop, so he did this for years and years. Fill your brake reservoir - you have to keep it full, so keep checking it - then hop in and pump the brakes a time or two. Get out and crack all your bleeders. Leave them open. Check your reservoir (remember, keep that thing full) and go pump the brakes, nice and easy, a couple times. When you get a solid amount of brake fluid out of a given bleeder, close it off. Check your fluid level. Repeat the process until each one of your bleeders has had a decent amount of fluid come out and has been closed off. Check your fluid. See if the brakes are hard. If they are, you're done. If not, read on. Pump the brakes a time or two and go to the furthest bleeder from the master cylinder and open it up so that brake fluid dribbles out and close it. Repeat on each wheel moving from the furthest to the closest. Keep your reservoir full. That's it. you're done. You don't have to believe it, but it works, at the risk of being lambasted on the interwebs here.... Mike
One brake line too close to exhaust heating brake fluid causing it to expand, applying one side faster than the other?
Very interesting theory. The exhaust passes through the frame rails on these cars. I don't think any portion of the exhaust comes close to the front brake lines, but it might come close to the rear lines. By the fact that I can feel the pull in the steering wheel, it seems unlikely that the problem would be in the rear, but I'd be willing to believe almost anything at this point.
I agree with Andrew Williams. I had the same problem with an F100 and it turned out to be a bad wheel bearing on the opposite side of the pulling wheel.
So, it's been a while. I've had some other mechanical issues to sort out, so I haven't been able to drive/test the car. I did replace the right front brake hose though since that seemed like the most popular diagnosis. Here's the deal: it is absolutely, positively the right front wheel that is the problem. It is acting like there is a one way valve in that line that holds pressure on that corner. Every time I apply the brakes, it gets tighter and tighter. It does this despite the new hose. On my way to the Jalopy Showdown, in stop and go traffic, I eventually had to pull off and let things cool down. Eventually, the wheel released and I could continue on. On the return trip, it seems as though the problem got worse. Despite using the brakes as sparingly as I possibly could, by the time I got home, that corner was crazy hot -- as in smoke rolling out of the fender well hot. In order to move the car back in the garage, I had to open up the bleeder on that corner. Once I did, the wheel would turn again. I'm going to replace the shoes on both sides up front, the wheel cylinder and the wheel bearings on the right front corner. Is there anything else that I'm overlooking that could possibly be at fault here? My working theory at this point is that the wheel cylinder was bad from the start, but has gotten a lot worse -- but that hasn't been proven at this point.
If one brake is dragging, it will slowly heat up as you dive. After it gets hot, that wheel won't stop. When you apply the brakes, only the other side will stop and pull to the good side.
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