77 front wheel locking up

[jtauxe]

On my new '77 Westy, the driver's front wheel locks up hard when the brakes are engaged hard. One nice long screech and a trail of rubber on the ground, though it does track straight.

Does this indicate the need for a new brake cylinder? It is perhaps no coincidence, then, that the bus came with some new parts: two cylinders, two brake lines, and new pads. The PO knew this was needed.

He'd also been driving around with the ebrake cables too tight. The back wheels would actually get quite warm to the touch. I loosened them, but still need to adjust them properly.

[spiffy]

Could be a bad line as well. Whatever it is it sounds as if either pressure is not able to release or something is sticking.

[Amskeptic]

On my new '77 Westy, the driver's front wheel locks up hard when the brakes are engaged hard. One nice long screech and a trail of rubber on the ground, though it does track straight.

Does this indicate the need for a new brake cylinder? It is perhaps no coincidence, then, that the bus came with some new parts: two cylinders, two brake lines, and new pads. The PO knew this was needed.

He'd also been driving around with the ebrake cables too tight. The back wheels would actually get quite warm to the touch. I loosened them, but still need to adjust them properly.

Cylinder? Caliper? Remember, the screeching side is the functioning side.
Colin

[vwlover77]

Cylinder? Caliper? Remember, the screeching side is the functioning side.
Colin

For sure???? If the pads are contaminated by grease, won't they lock up prematurely? I know my rear drums did when my axle seal failed and they got soaked in greasy oily stuff.

[jtauxe]

Cylinder? Caliper? Remember, the screeching side is the functioning side.
Colin

Yes, of course caliper. I actually have not delved into the front brakes of a late bay, and I was just naturally thinking of my old '69, which has drums in front. So, these cylinders left by the PO must go to the back brakes.

You are correct that hydraulic brakes will fail by NOT grabbing, rather than locking up. If the screeching side is the functioning side, then the front right brake is not working as it should. But why would the driver's side lock up instead of just work normally and cause the vehicle to brake with less overall force?

And what is indicated here? Replace the calipers? It looks like they're not so easy to rebuild. Delve into the rear brakes (couldn't hurt)?

It seems to me that this could be serious, and I should probably not drive the bus until it is dealt with. Thoughts?

[chitwnvw]

Well there's some easily replaceable part, brake lines, pads. Actually, the front discs are pretty primal.

[Amskeptic]

But why would the driver's side lock up instead of just work normally and cause the vehicle to brake with less overall force?

It is true that rear brakes can lock up from fluid contamination, but that is on an unloaded axle. In the front, under the majority of the load, fluid contamination sends your friction coefficient all to hell.

The *usual* culprit on a front is a frozen caliper piston, but *usually* you also get plenty of swerving. If you do not experience swerving, then we have to think a bit. Pull the pads, hopefully they are worn a bit, and let us know if they are equal thickness. Also check to see how easily the pistons retract as you spread the pads to pull them out. I have had good luck with channel locks, big ones, to squeeze the pads or pistons in.
If you have a frozen piston, well, let us know that too.
Colin

[Ritter]

For what it's worth, my 78 was doing the same thing. I think it may be that the left front was the only brake working properly. I replaced the rubber hoses and the rear brake cylinders that were leaking and new rear shoes. I did not touch the front brakes except for the new rubber lines (and one metal one that I broke). She stops mighty nice now.

[chitwnvw]

A minor hijack here. Does anyone have a trick or hint for replacing the rear drivers rubber hose. It doesn't hook up like the others, it goes into a splitter and you really don't have the leverage you can apply to the other hoses. It also seemed to be a different size, although that might be PO nonsense.

[jtauxe]

For what it's worth, my 78 was doing the same thing. I think it may be that the left front was the only brake working properly. I replaced the rubber hoses and the rear brake cylinders that were leaking and new rear shoes. I did not touch the front brakes except for the new rubber lines (and one metal one that I broke). She stops mighty nice now.

Well, that's interesting. Upon closer inspection, what the PO left in the bus was a full set of rear shoes, a pair of cylinders, and two new hoses. Looks like I've got all I need to attack the rear brakes, so I'll do that and see how she goes. Or stops, rather.