intermittant slipping handbrake

[Don 130]

The handbrake on my 130 occasionally slips enough that it won't hold the truck on a very slight slope. Other times it will hold as if it's been pinned. It can alternate between these two situations within the same day. The problem has only been apparent since the gearbox was removed for a reconditioning about two years ago. The lever usually holds the truck on about the third click if it's going to. I'd be grateful to hear of any clues.
Don.

[justinc]

Have you removed the park brake drum and checked inside for oil contamination?

JC

[JDNSW]

My view is the same as Justin - leaking rear T/C seal getting oil on it. There is supposed to be a drain that allows leaking oil to not get on the brake, but it often blocks.

Small quantities of oil will not affect the grip - in fact, the oil may become sticky, and help it (as long as you do not use the handbrake for stopping and get it hot!), so my guess is that the seal is leaking, but the drain is only intermittently blocked, so that some of the time there is enough oil to prevent gripping, other times there is not.

(I speak from experience!)

John

[Psimpson7]

Drum may be out of round aswell? Sure mine is.

Does the hand brake lever always stop at the same postion / feel the same

[Don 130]

I have'nt actually checked anything as I figured it was someting internal and also wondering if it is somehow due to the gearbox job, (by the way, the transfer case also got new bearings throughout) in which case I'd drop it in the lap of the mechanic. I'm sure the drum is not round, but I don't think that's the problem, feels more like the oily suggestion. I'm off outside to look for a blocked breeather now. Don.

[JDNSW]

I have'nt actually checked anything as I figured it was someting internal and also wondering if it is somehow due to the gearbox job, (by the way, the transfer case also got new bearings throughout) in which case I'd drop it in the lap of the mechanic. I'm sure the drum is not round, but I don't think that's the problem, feels more like the oily suggestion. I'm off outside to look for a blocked breeather now. Don.

A blocked breather could cause leakage, but the drain you are looking for is a groove in the casting on the back of the speedo drive housing where it mates with the backing plate. You should see traces of oil both where this drain is, and at the join of the backing plate and the drum.

If the transfer case has recently been worked on, I would bet on the oily bit - seal either incorrectly installed, damaged during installation, or the sealing surface on the drum/flange is damaged, or the output shaft is wobbling due to loose bearings.

John

[Don 130]

I had a look and sure enough there's oil present. I found a little port thingy facing down on the underside of the centre casting. I poked around inside it with a piece of wire and couldn't feel any sort of Hole in there that may need unblocking. I tried to post a picture of the port to get confirmation but the camera wouldn't speak to the computer. I'll have to have another look to find the hole near the speedo cable drive. I'll be disappointed if it's due to some bad workmanship. The gearbox and transfer case were reconditioned by a highly respected workshop but taken out and put back in by our local mechanic . I'm of the opinion that the synchro on second gear is faulty.....it grates far too often for my liking, and on mentioning it iv'e been told ' oh it's ok you just need to make the shift bit slower, then it'll work smoothly'. Trouble is ,if I'm pulling or carrying a load up a hill and need to get second gear, it has to be done relatively quickly or I loose too much speed and can't carry on in second so have to go back to first which can also be a drama.Anyway, winge over, I'll have another look tomorrow. Don

[JDNSW]

I had a look and sure enough there's oil present. I found a little port thingy facing down on the underside of the centre casting. I poked around inside it with a piece of wire and couldn't feel any sort of Hole in there that may need unblocking.......... Don

I'm not certain it goes straight through in the sense of being able to poke something through it. And it may have been blocked (inadvertantly) by sealant when it was being assembled, which would stop your wire. Or you may be looking in the wrong place. But if there is oil on the backing plate, a leaking seal will be the problem.

John

[justinc]

2nd gear can be a bit baulky when really cold, even from new some were like this but usually Syntrans 75W85 will help. I don't agree it should be grating after the first few shifts in the morning etc. That isn't how they are supposed to be at all.
If the rear seal is leaking into the park brake, it could be down to the flange, I usually replace the flanges when rebuilding TF cases unless the seal surfaces and splines are immaculate. Genuine Corteco seals should be used too.

JC

[Don 130]

Thanks Gentlemen, I'll speak to the mechanic when next service comes around(soon). I feel better going armed with some relevant info.Don.