Alright, I'm having a really strange and irritating problem with my brakes on my 86 samurai. I just swapped the rear brakes over to Samurai discs off of an 86 or 87. The rear end is welded (even though that shouldn't have anything to do with it). Prior to the conversion the brake pedal would go to about half way down before really grabbing. From there, the pedal was pretty solid. No leaks or air getting sucked in anywhere.

I used the Spidertrax setup with the lines so the proportioning valve is on the forward line on the master cylinder, the rearward line was untouched. I've swapped the 2 lines on the manifold on the passenger frame rail like the instructions state. Now the forward lines (on the manifold) are going to the front brakes and the rearward lines (on the manifold) are going to the rear brakes. I then replaced the hard lines on the rear axle with the ones in the kit. I used my old stock front brake lines to go from the hard lines to the calipers. Nothing really out of the norm on the conversion.

After bleeding, bleeding, and more bleeding I finally got the pedal to where it was before.

The problem that I'm having is driving me crazy. No one I know has any idea of what the problem might be. If I'm going down the road the brakes feel fine. If I'm going slow and turn hard left (or right) and stomp on the brakes the pedal goes to the floor before grabbing. A quick pump and the pedal is where it was before. When going straight again, it's fine.

I can't seem to find any leaks in the system. I've tried moving the soft lines on the front axle while someone held down the pedal to see if there was any change, but nothing did.

Anyone have any idea what this could be. This is driving me crazy. Unfortunately I can't seem to find a shop to even look at the system and pressure test it since it's "no longer stock". If anyone knows of a shop in Nor Cal that will check altered systems let me know.

if there are no leaks then you m/c is bypassing.......get a new one, or the proportioning valve is letting fluid from one side of the system get to the other..sounds like these can be the only two problems (logic here: no leaks, the fluid has to go somewhere).....anyone else?

In my experience, the master cylinder is the most common problem with brakes like you describe. Although I cannot explain the "intermittent" nature with air bubbles, but Samurai brakes are sometimes almost impossible to blead. Since it is cheap and easy, I would try power/vaccum bleadng the brakes once just in case. Probably isn't the problem, but it is cheap and easy. I have had Samurai brakes "appear" to be bled, only to have the peddle go clear to the floor the next day, because small entrained air bubbles over time converge into a large air pocket. Perhaps, you cvould have the same thing going on, then you stomp the peddle, emulsify the air/fluid making the peddle feel firmer. Anyway, a long shotm but worth a try.

I assume you already talked to Spidertrax? Those guys are so helpful I would think they would just about fly out here to help you with it if you were really having troubles. I recently got a power steering pump from them that didn't work out right at first. They spent several hours with me on the phone, called a bunch of other sources, and we finally got the problem figured out. If you called them once, call them again. They'll help you get it figured out.

1 man power power vac bleeders = Gooooood Brakes

Anyone know of a place to have it power/vacuum bled in the area? So far all the shops I've tried won't touch it since it's not original.

I've tried having someone on the pedal pumping fluid through, pumping up the pedal then opening the line to clear it, and the small hand pump style vacuum bleeders.

do you have a residual pressure valve in the rear brake line?
If not , it is possible for the calipers to "open" , taking them away from the face of the rotor . This forces fluid out of the calipers , back to the master cylinder. When you apply the brakes , the calipers have to close back down to clamp the rotor. Check it out....anyone else have input ?

Originally posted by Roksamy
do you have a residual pressure valve in the rear brake line?
If not , it is possible for the calipers to "open" , taking them away from the face of the rotor . This forces fluid out of the calipers , back to the master cylinder. When you apply the brakes , the calipers have to close back down to clamp the rotor. Check it out....anyone else have input ?

This sounds like it may be your problem.Your rotor or a bit off axle play may cause some movement that is pushing your cailber back and this would be why it's happening when you turn.

But that may not be it.Try changing cailpers.Your could have a bad one.Try bleeding your cailper on the back with it off the zuk.Tip it so theres no way for air to trap in the upper part of the cailper.

Just some stupid stuff to try.It's amazing on what little things might just work for ya.Check flex lines for bubbles.Check master.

Switch master for another one.

If you elimnate all moving parts sooner or later something has to be it.

JUST my opinion,Brakes can be a pretty hard thing to deal with.

Make sure your bearings are set right in the front.If they are loose they will walk the piston back in a bit and then you will have to push it back out.The other thing that may be happening is a steering stop or something like that hitting the caliper and forcing it to push the fluid out as well.If you have rubber hoses instead of stainless you can "LIGHTLY" clamp all the lines then with the pedal pushed hard release one at a time till you feel a dramatic change and that will isolate your problem.If your lines are clamped and the pedal is not hard as a rock it's in your master.If you apply the brake slowly does it sink to the floor but a hard shot and the pedal is firm?If so it is your master.Good luck!

rob, thanks for the suggestion of clamping off the lines to isolate the caliper off. For some reason it didn't even come to mind to try that.

As it turns out it looks like the passenger rear caliper is bad. When I clamped off both rear softlines the pedal is solid almost instantly. Then I unclamped the driver's side. The pedal went down slightly farther, but was still solid. While turning was no different. Then I unclamped the passenger's side. The pedal went down a lot farther and felt slightly spongy. While turning the pedal went to the floor.

So, does anyone happen to have a spare passenger caliper that they don't need?

I do - but there's a hitch. :)

You have to take the whole 2wd front axle, and both calipers.

And, I'm not far from you - it's in Pinole.

Originally posted by tdavis
I do - but there's a hitch. :)

You have to take the whole 2wd front axle, and both calipers.

And, I'm not far from you - it's in Pinole.

That's fine with me. I can always figure out something to do with the left overs. The calipers are the same on the 2wd and 4wd right?

To the best of my knowledge.

Originally posted by tdavis
To the best of my knowledge.

I think they are also. I just posted a question on the ORC board for confirmation. If they are the same I can come and pick up the axle most anytime.

I can find out tomorrow for sure. If the calipers fit I can let you know and setup and time to pick up the axle.

It appears the consensus is they are identical..

I've PM'd you with contact & location information.

just go down to autozone and buy a vacume pump brake bleeder you just hook it up to a cracked {open} brake bleeder and and start pumping you watch the air come out thru the clear hose and when it stops close the bleeder...................

with mine i can bleed all 4 corners in less than 15 minutes or less and it works every time no more headaches.....

and it should be less than 30.00 bucks......a very cool tool