HELP: Stuck brake? Diff? Transmission?

[ashooter]

'92 FJ80 (3FE and drum brakes in the rear - similar to a FJ62)... This problem has been evident for 6 months or so, but seems to have gotten noticeably worse just today.

6 months or so ago, I started the truck, released the parking brake, put it in reverse to back out of the driveway and it felt like the parking brake was stuck. I could feel that the engine was working against something to make the truck move - not rolling freely. So I engaged and disengaged the parking brake a couple of times, backed out of the driveway, then went on down the road with no more problem. Also, the problem mostly seems to be evident when the truck has been sitting for a while.

This same kind of thing has happened about 50% of the times I've cranked it up in the morning since then, but I sort of learned to live with it since it always loosened up pretty quick and I just did a brake job a year or so ago (less than 10k miles). Also I only drive this truck once or twice per week.

In that 6 months or so, I have noticed that this "brake sticking" sometimes happens when the parking brake had not been engaged at all. In those cases, I'd drive forward a couple of feet, reverse a couple of feet, then forward a second time would always seem to loosen things up so the truck would roll freely. It has NEVER happened except on start-up, meaning that it's not like I stop at a stop sign and have the brake get stuck. It only happens when I first start up the truck.

My first question is: How can I be sure this is a brake problem and not something going on with the transmission or one of the diffs?

My second question is: Has anybody else had any "symptoms" like this?

edit to add: There IS rolling resistance. Not an issue with power not going to the wheels, but something holding the wheels tight... which is why my brain defaults to a brake problem.

Thanks

 

[fj4068]

Some things I can think to check:
- caliper bolts that have loosened and allowed a caliper to rotate around one bolt into the rim
- damaged wheel bearings and/or spindle

 

[ashooter]

Checking caliper bolts sounds like a good idea! I don't think it has anything to do with the bearings, simply because I repacked them at the same time I did the brake job... then put at least 5,000 miles on the truck before this issue started. Also, it seems to me like if it was a bearing problem, I'd hear it or feel it differently. This really feels like the parking brake is stuck, then pops loose and work fine. Feels exactly like when you try to drive off with the parking brake still engaged - the truck will move (slowly), but you feel the brakes holding.

I plan to put it up on jack stands tomorrow and give everything a close look to see if I can figure out what's going on.

 

[ashooter]

Well I'm stumped...

I put the front on jack stands, wheels spin freely. Same deal for the rear. I engaged and disengaged the parking brake a few times - holds tight when it's supposed to, and wheels spin free when it's released.

Anybody have any clues about where I should look next?

 

[jwilber]

I have the same issue on my 91 I'm pretty sure its a rear brake problem but not positive. ...subscribed

 

[CJF]

Anybody have any clues about where I should look next?

Sure;

Pop the wheels off and thoroughly inspect the brakes, especially inside the rear drums.

 

[ashooter]

Wile E Coyote in the 60 Series forum suggested flushing/replacing transmission fluid, so...

I never did get a chance to pull my drums and eyeball the insides. Up on jack stands they seemed to function fine, and I knew I was overdue for a transmission fluid swap, so did that first. According to my maintenance book, I've done two drain/fills with Mobile 1 in the last 30,000 miles (6.5 years). I could have sworn I did a full "fluid transfer" when I first bought the truck, but the book said otherwise - oops!

Drained/filled, then hooked a piece of hose to the outflow from the cooler in front of the radiator, started/stopped the engine to pump out and replace the fluid 2 qts at a time until I topped off with the last of 18 qts of Valvoline synthetic ATF. Not cheap, but I figured it's a helluva lot cheaper than a new transmission.

Everything was pretty warmed up from starting/stopping the engine and shifting through R, N, and D while pumping out the old ATF. but everything seemed to work perfectly when I took it for a test run afterward. No "sticking" or "dragging" feel when starting out forward or reverse, and shifting was noticeably smoother when getting up to highway speed. Still not Chevy-smooth, but it's always felt a bit rough/clunky downshifting to accelerate or climb a hill on the highway.

Anyway, I will update this thread if there's any change in performance, but for now it seems like doing the fluid swap has fixed the problem.

 

[blkprj80]

Not saying it's the same problem you have, but my 71 gmc would stick sometimes. It turned out to be a 90wt leak and one of the rear drums was saturated with sticky 90wt. The seal had leaked. I rebuilt the brakes and replaced the seals and the problem was gone. Mine would stick when I backed up and used the brakes. Put it in drive and it felt like someone was holding me back. Back up without brakes a bit and then it wouldn't stick. It was worse after sitting all day at work, and when it was cold outside.

 

[ashooter]

I'll probably pull the drums and take a look at them when I get a chance. Brakes did get kinda squirrely when I had a rear axle seal go out a year or two ago, but I could see diff oil leaking out around the bottom edge of the drum. This feeling was very different than that was, though. Much more pronounced.

 

[ashooter]

Well, after I adjusted the shoes a little, the truck drove fine for maybe 100 miles over a couple of days, then sat under the carport for a week or so... Started it up one morning when it was about 38 degrees, and the brake stuck again.

I got it loosened up enough to drive to the local shop and dropped it off a week or so ago. The mechanic thinks he has it isolated to one of the rear drums, but neither he nor I can figure out why it's sticking. Spins free when you pull the drums off, so doesn't seem to be the diff(s) or transmission. It is not the parking brake cable, not a broken spring, not a cracked shoe, or anything else obvious. I'm thinking maybe it's one of the piston thingamjigs that pushes the shoes out against the drum, so I'm just going to try to order some parts and start replacing stuff, hoping to accidentally fix it.

Anybody have any new ideas?

 

[turbo5s]

On an old mazda truck, weak return springs would allow the brakes to drag occasionally. They seemed to work fine on jackstands, but I am thinking the self-energizing aspect kept them from releasing when I released the brake pedal. Could tell installing new springs that the old ones were weak.

 

[Cove]

I have the same issue on my 92. It will sit in the garage for days & when I go to drive it there is a temporary drag. I had it to our hunting camp last week & went to leave (sitting on a dirt/slate road) and the left rear was locked up. It freed up after 30' or so. When I took a closer look I could smell gear oil. Time for seal replacement. When I got it home I removed the drum and cleaned it, pads, retaining springs & backing plate with brake cleaner. Temporary fix until after hunting season. Haven't had any sticking yet. Plan on replacing both rear seals next week.

 

[ashooter]

...When I took a closer look I could smell gear oil. Time for seal replacement....

I thought of that, since I had the same problem a couple of years ago, but the seals look good and the insides of the drums is dry.

 

[jonheld]

Have you inspected the bell cranks on each rear wheel for proper operation? They are known to stick and are spring loaded. So it is possible that when you release your handbrake 1 or both will temporarily lock and slowly release over time.

 

[ashooter]

Have you inspected the bell cranks on each rear wheel for proper operation? They are known to stick and are spring loaded. So it is possible that when you release your handbrake 1 or both will temporarily lock and slowly release over time.

I have gotten it rolling, then gently applied the hand brake, then release and it begins rolling smooth again... Done this on the ground and up on a lift, turning the wheels by hand. It seems to be related to the hydraulic brake system, and seems to be one of the rear drums - the left one, if I remember right.

I'm guessing (hoping) that replacing all of the guts in the drums (including the whole piston assy) will fix it. Neither me nor my mechanic has been able to isolate it any further than "one of the drums"... Driving us both nuts trying to figure it out. But on the bright side, at least it does not seem to be in the diff(s), t-case, or transmission.

 

[jonheld]

So I will assume the answer to my question is no.

The reason for my persistence is that these are a known problem. The pivot pin in the mechanism will corrode over time. This can cause the bellcranks to stick. You reported that this happens after the vehicle has been sitting. I take that to mean that the handbrake is applied. If you release it and one of the bell cranks doesn't immediately relase, it would cause EXACTLY what you're experiencing. It's possible that after a while (and add some heat), the pivot frees up.

You need to remove each bell crank (2 bolts, a cotter pin and a cable) and inspect them on a bench. They should move easily with no resistance.

The non-ABS version of the 80 Series brake system is very simple. A caliper rebuild kit from Toyota is around $22 for both sides. There is also a rebuild kit available for the rear brake cylinders for about the same price.

The rubber boot of the bellcrank helps keep water and poop inside.

 

[jonheld]

Please understand. I'm not saying it MUST be the bell cranks. What I'm seeing is you and your mechanic GUESSING at a problem without eliminating parts that can't be part of the problem.

Don't be so fast to throw money at this.

 

[ashooter]

Thanks jonheld. I will check out those bell cranks when I start tearing into the drums and see what I can see.

However, I have left the truck parked for up to a few days without the parking brake engaged and it still locks up. Just based on jacking around with it off and on for the last month, I really do not think it has anything to do with the hand brake part of the system. Seems more likely it's part of the wheel cylinder.

 

[bdjutt]

Thanks jonheld. I will check out those bell cranks when I start tearing into the drums and see what I can see.

However, I have left the truck parked for up to a few days without the parking brake engaged and it still locks up. Just based on jacking around with it off and on for the last month, I really do not think it has anything to do with the hand brake part of the system. Seems more likely it's part of the wheel cylinder.

I'm new to LC family. I have a 1992 LC, have never, or rarely used the parking brake , so believe my issue anyway is not related to parking brake, but I'm having a similar issues to yours. At start up, usually after sitting for several weeks, my rear passenger side wheel/tire locks up. It breaks free sometimes within 10 to 20 feet, but today it was 100 feet or so of dragging the back wheel, then several loud clucks and all is good. This is a reoccurring issue so I'm looking for how you or someone else resolved theirs? Any advise would be great. Thank you all

 

[Malleus]

Do yourself a favor and check the emergency brake operation; it takes less than 5 minutes. I completely rebuilt the wheel end systems on two of my 80s before the problems I was having were solved. Just reach behind the wheel and pull the cable by hand. You may have to peel the beelcrank boot back to get a good look, but I doubt it. If it moves freely, at the bellcrank, pull the wheel and drum and then do the same test.