Background: '55.1 stock bendix brakes brand new everything, lines,master, wheel cylinders, springs, shoes, the whole shebang. Installed and adjusted as per shop manual. Truck was pulling VERY badly to left upon braking. Removed left hub/drum to inpect and everything was fine. Re-adjusted front brakes and it improved greatly. However, truck pulls to left still, and get this, it does it WORSE once it has been driven for a while. Seems that after the brakes heat up some, it pulls worse to the left. Once it cools down, brkaes work more evenly. My local old timer friend/mechanic says it's just the shoes bedding in, but I have driven it several hundred miles already and figure the shoes should have bedded in already. Any suggestions? Andy
The shoe's on the other foot! Andy, you know I'M no expert, but I was thinking about brake fade. When you ride your shoes to much, they glaze/overheat/won't stop. I wonder if the OTHER shoe is actually doing this, and the driver's side is the only one doing the real (or most of the) stopping? (This is why I'm going disc up front~ You haven't tried driving in the rain this way yet? That could be r-e-a-l hairy...) Good luck, Andy!
Andy , are the return springs of equal strength? The left one may be weak and allowing the shoes to rub-- thus overheating--- OR the adjustment may still not be quite correct-- Good luck, Glenn
Brakes Andy : did you bleed the brakes , making a hard pedal? If there is air in the lines the fluid can heat up making erratic brake pressure. Also did you turn the drums or put in new ? check the brake shoes on each side to make sure you put the primary shoe in the front on each side (the short shoe). maybe this will help. Gene
The very first thing to do is to wait for Nate to weigh in. In the meantime check the primary and secondary shoes as Gene suggested and then you might raise the front and have someone step on the brake easy at first and then progressively firmer. Turn each wheel by hand and see if they are first dragging and finally locking up at the same pressure. If they are adjusted properly and one wheel drags and locks up before the other then there is something in the fluid supply that isn't right. The only mechanical thing I've run into is if the drums have been turned and a ridge left where the cutting tool wasn't run into the drum far enough. Champhering the lining where it hangs on that ridge is a down and dirty way of curing the problem. If one side isn't getting as much fluid/pressure as the other check the flexible rubber line first, I've had even new ones that were the culprit--usually from the end being crimped on improperly. As each checks out OK keep working your way back to the MC, each line, hose, and fitting. I'd bet you will get it whipped. Let us know what you find. P.S. If you know someone with a brake pressure gauge you can check at each wheel cylinder to compare.
Too late ! Everything I would have said , has allready been said.... Remove both drums and eyeball the whole mess , if the longer lining shoes (secondary) are not on the rear of both brakes , fix that , then look at the springs as they MUST match perfectly , you can swap parts from side to side to see if the problem changes to pulling to the right . swap the shoes first , then the springs as fading with heat buildup usually indicates bad shoes , not springs nor hydraulics . I'm thinking it's either shoe lining contaminated or the drums are severely mis - matched size wise . I know you've prolly allready tried the stick trick ? . Is the brake pedal hard as a rock and high ? . When I bought my '49 , everything in the brakes was new but it didn't stop atall and pulled badly , I had to re-adjust the brake shoes every 200 miles or so for a month or two before it finally began stopping correctly . Please keep us posted Andy .
Springs new, primary shoes where they should be, no contamination, bled properly, pedal high and hard. Gonna be like Nate and adjust them a lot and see what happens first. I like the idea of the brake pressure gauge. Never even heard of one before. That's what I like about this forum. I'm thinking it's a hydraulic problem so that would be the way to go. I will adjust often as that seemed to make the issue better. Drums are old and I did NOT turn them as per Nate. They look good and brakes do not pulsate, they just pull to left. As I said, it got better after I adjusted them, so I will do it again and again before tearing the whole system apart. Thanks to all for all the great suggestions. Andy
Last thought : take the brake drums off and toss 'em in the 'Burb , have the local brake shop measure them to see if one is maybe significantly oversized from prior turning... Or just swap 'em left to right , re-adjust the see what transpires . I just got a nifty infra-red thermometer from Harbor Freight for $19.95 , it was the $39.95 one but the girl liked me (I guess) as she sold it to me for $19.95 right after telling me it wasn't on sale , I am now using it to check things all over the place , it reads in Celsius as well as Fanenheight (! SP !) , in case Neil wants one , so far I've discovered my Mercedes Deisel's temp. gauge reads 12° higher than the actual coolant temp. and that as I'd thought , the right front brake caliper drags ever so slightly as the hub temp. is hotter on the right that the left after a spirited run.... You can use this tool to help diagnose the pull after it gets hot . the hotter side should drag less unless there's residual brake pressure .
A good rule is to always turn drums and arch the shoes to fit the drum they are going on. On single cylinder master cylinders the front left gets pressure 1st, then the right then the rear. I know pressure is supposed to be the same everwhere but when you hit the brakes the left front wants to grab because the right has not seen pressure yet. If the drum is not turned and shoes arched they take much longer to break in. The right front needs to be tightened down to where it is hard to turn by hand and the left a little less. I had mine perfect and some jerk ran the light. I had to lock em up at 45-mph. After that they needed to be readjusted and a little fluid was missing.
