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View Full Version : Brakes: mysterious binding issue - M5 pickup



tedtaylor
06-21-2018, 07:40 AM
SYMPTOM: front brakes bind, apply brakes, come to stop, stuck on, binding going forward. need to back up - brake, then they are released.

REPLICATED: I jack front end up, forward rotation of wheel by hand, wife applies brakes then foot off pedal. I can NOT rotate wheel forward, it is still locked up, but if I rotate wheel backward from this locked position, brake releases. this happens to both sides.

BACKGROUND: I just had all 4 wheel cylinders re-sleeved at Apple Hydraulics, rebuilt MC, bled air, adjusted shoes, all new riveted shoes, all clean parts, all moving parts with red brake grease (slightly) and all parts move easily, springs strong and retract. Brake pedal high and firm, brakes stop well with no side pulling or other abnormalities.

I'M AT MY WITS END, Please HELP with definitive solution, not just guessing.
Thank you!!!!
:)

jackb
06-21-2018, 07:47 AM
Brake pedal play might be too tight. You need the brake pedal to move at least 1/8th of an inch before M/C rod moves...

gordr
06-21-2018, 08:19 AM
I don't think it's hydraulic issue, since that would make the brakes drag regardless of the direction the wheels were rotating. I would be looking for shoes installed the wrong way (leading vs trailing), or maybe return springs installed wrong. Also, it may help to chamfer the ends of the brake linings with a file or grinder to about half their depth. That used to be standard practice to reduce squeaking issues.

Also, have drums been turned beyond their oversize limit?

jrlemke
06-21-2018, 08:41 AM
How about the rubber lines? have they been replaced? They can look good on the outside, but be bad on the inside. -Jim

TWChamp
06-21-2018, 11:24 AM
Make them bind again, then open the bleeder and see if they release.
If they do, then make them bind again and crack the line open at the master cylinder to see if they release. No lease this time, then look for a bad hose on that wheel.

tedtaylor
06-21-2018, 11:39 AM
thanks for initial responses:
jackb = there is some play in pedal before actually actuating, I only meant to say the pedal is high, but actually 1/4 stroke before they work.
gordr = good idea, when I have the drums off.....again, I will do that. I do not know the tolerences/dimensions of the drum. I have read elsewhere about chalking the shoes and see the rub off from drum contact.
jrlemke = hoses are brand new when installed a decade ago, no visible external cracking, seem pliable enough, fluid flow one direction is good while bleeding, so I assume you mean possible reverse flow blockage?
TWChamp = good advice, I will consider doing that.

ALL - this truck was restored a decade or so ago and stored in a container ever since, thus my need for overhauling the hydraulics. I have seen all new metal brake lines, all new rubber lines, all new shoes, and the drums have yellow paint markings, like they may have been junk yard salvage? I would like to assume they were in proper working order then, however my discovery of leaking seals after slight honing leads me to believe the re-sleeving was the right thing to do. The brakes are otherwise working superbly, if not for this locking up/binding issue...…
UGH! !@#$%^&

tedtaylor
06-21-2018, 11:52 AM
Make them bind again, then open the bleeder and see if they release.
If they do, then make them bind again and crack the line open at the master cylinder to see if they release. No lease this time, then look for a bad hose on that wheel.

sound plausible, however remember that this "temporary" locking instantly releases with the slightest reverse rotation of the wheel, and this happens on both front sides, so sounds unlikely to be hydraulic, so i'm leaning more towards a mechanical/physical issue. When it temporarily locks, I can not more it any further in the same direction, it's locked, however just reverse the wheel and it's free.

If only the drums where made of clear glass so I could see what's going on inside.! :)

BARNSILVER
06-21-2018, 11:57 AM
SYMPTOM: front brakes bind, apply brakes, come to stop, stuck on, binding going forward. need to back up - brake, then they are released.

REPLICATED: I jack front end up, forward rotation of wheel by hand, wife applies brakes then foot off pedal. I can NOT rotate wheel forward, it is still locked up, but if I rotate wheel backward from this locked position, brake releases. this happens to both sides.

BACKGROUND: I just had all 4 wheel cylinders re-sleeved at Apple Hydraulics, rebuilt MC, bled air, adjusted shoes, all new shoes, all clean parts, all moving parts with red brake grease (slightly) and all parts move easily, springs strong and retract. Brake pedal high and firm, brakes stop well with no side pulling or other abnormalities.

I'M AT MY WITS END, Please HELP with definitive solution, not just guessing.
Thank you!!!!
:)
The master plunger rod needs to be shortened/adjusted.

TWChamp
06-21-2018, 02:07 PM
Are the linings bonded or are they riveted?

If they are bonded, be sure they aren't coming loose. A picture with the hubs off would be great.

62champ
06-21-2018, 04:10 PM
From your description, it sound as though the shoes are "sticking" to the drum and will not release until a slight movement backwards. I wonder if the shoe surface is old/defective or if they just need to be used so they will seat to the drum? Maybe a dozen neighborhood miles with lots of braking and releasing might get them working properly.

Jerry Forrester
06-21-2018, 04:33 PM
From your description, it sound as though the shoes are "sticking" to the drum and will not release until a slight movement backwards. I wonder if the shoe surface is old/defective or if they just need to be used so they will seat to the drum? Maybe a dozen neighborhood miles with lots of braking and releasing might get them working properly.

Yeah, drive your truck 12 miles around your neighborhood IN REVERSE while applying the brakes every 15 feet. That'll fix it for sure.
Sorry Patrick. I couldn't resist. It was just too easy.

jrlemke
06-21-2018, 04:35 PM
How about a little "block sanding on the shoes? Maybe a little inside the drums too.- Jim

62champ
06-21-2018, 04:40 PM
Yeah, drive your truck 12 miles around your neighborhood IN REVERSE while applying the brakes every 15 feet. That'll fix it for sure.
Sorry Patrick. I couldn't resist. It was just too easy.

Its all good - if it was someone I knew, I would suggest switching the backing plates and all attached to the opposite side - then they would only lock up when you backed up...

tedtaylor
06-27-2018, 06:47 AM
in the end, i bled the system again (hidden air found) and re-adjusted, i also shortened the brake actuator rod a bit, but i think the best remedy was just using them and wearing them in. I have since obtained a decent pedal 3/4 high and firm, even stopping, no pulling and seemingly now no binding. so a combination of many little things to make this brake job successful. See you at the parade! :)

RadioRoy
06-27-2018, 10:20 AM
Thanks for reporting the solution. That adds to the collective knowledge base that makes this forum so valuable.

tedtaylor
07-25-2018, 05:25 PM
OK, I spoke too soon. I still have a problem. If the truck sits a couple days without use, I go to use the brakes and the pedal goes further down than usual, the brakes lock up suddenly and also pull to one side abruptly, they also lock up and bind.....
Now to rememdy this, I pump the brakes a few times, back up...brake...pull forward....brake....back up....brake, and so on. repeating this process seems to eventually work out. The brakes soon have a full pedal, no longer pull, no longer bind/drag, and work normally.
Sooooooooo having said that, i'm lead to believe since they "eventually" work as normal, than mechanically there is nothing wrong, but i'm inclined to think an air bleed issue? But if that were so, wouldn't I have fluid loss???
Very frustrating.....
any suggestions???
thanks
TED

thunderations
07-25-2018, 07:55 PM
Still have air in the lines. Bleed the brakes again and drive it, using the brakes hard. Do this several times until all the air is out.
The air is captured in the lines somewhere, but there would be no fluid lose. Keep the MC full at all times.
All your symptoms are related to air in the lines. Pumping the pedal pushes more fluid towards the slave cylinders, but does not expel the air, just allows fluid to operate the slaves instead of air. The air just moves to another area of the system.

tedtaylor
07-26-2018, 08:44 AM
well explained "thunderations" and makes sense. I'll have to do that....again! I just suspected air "getting into" the system somehow since the brakes appear to work fine, but eventually become problematic, thus the expectation of a leak and fluid loss, but your description seems to fit.
THANK YOU.
sometimes the most obvious is the most elusive!

Mrs K Corbin
07-27-2018, 07:15 AM
Are you getting ANY fluid out of a drum? I had the same thing happen after a Sleeve job, and it turned out that the sleeves were too "slick" and the fluid was bypassing. I ended up replacing the wheel cyls with Brand New after nearly losing my newly restored truck within half a mile of the Museum. (Ran a light with no brakes, yanked it into a parking lot and did donuts till it stopped). Did you know that if the rear brakes get wet with hydraulic fluid, the emergency brake doesn't work either?:ohmy:

- - - Updated - - -

Are you getting ANY fluid out of a drum? I had the same thing happen after a Sleeve job, and it turned out that the sleeves were too "slick" and the fluid was bypassing. I ended up replacing the wheel cyls with Brand New after nearly losing my newly restored truck within half a mile of the Museum. (Ran a light with no brakes, yanked it into a parking lot and did donuts till it stopped). Did you know that if the rear brakes get wet with hydraulic fluid, the emergency brake doesn't work either?<img src="images/smilies/ohmy.gif" border="0" alt="" title="Oh My" smilieid="15" class="inlineimg">