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ZUKIWORLD Discussion Forum => Suzuki 4x4 Forum => Topic started by: g35-coop on March 09, 2012, 03:16:42 PM

Title: Brakes locked up!! HELP
Post by: g35-coop on March 09, 2012, 03:16:42 PM
Ok so my front brakes are both locked up.  I have put new brake lines on and changed the calipers!!  Where do I go next? Any advice would help.  Thanks
Title: Re: Brakes locked up!! HELP
Post by: Capt on March 09, 2012, 06:02:40 PM
First, ...ON WHAT?
If you have ABS, check the Service Repair manual for this model on the correct Bleed Method as some have a specific
order to get all the air out.

CAPT
Title: Re: Brakes locked up!! HELP
Post by: g35-coop on March 10, 2012, 08:04:14 AM
Its a 1986 samurai. 
Title: Re: Brakes locked up!! HELP
Post by: mrfuelish on March 10, 2012, 10:34:45 AM
how much free play do you have on your brake pedal? your back brakes should be dragging a little also if there is not enough free play but not near as much as the front.
Title: Re: Brakes locked up!! HELP
Post by: g35-coop on March 10, 2012, 10:50:16 AM
There is zero free play.  As soon as I touch the pedal they lock up.  And over a time like and hour or so,  I can turn the wheels by hand.  I figured it was a collapsed brake hose so I changed both of those and still its locked.
Title: Re: Brakes locked up!! HELP
Post by: mrfuelish on March 10, 2012, 06:41:05 PM
ya you need more free play on your master cylinder, you could take the two nuts off of it and pull it out a little bit and see if there is an adjustment there.
Title: Re: Brakes locked up!! HELP
Post by: g35-coop on March 10, 2012, 11:04:05 PM
ok ill check it out in the morning
Title: Re: Brakes locked up!! HELP
Post by: fordem on March 11, 2012, 06:09:33 AM
Another possibility is blocked fluid return ports within the master cylinder itself - I would not suggest fiddling with pushrod adjustments to set the free play on the master cylinder as a first step, those are not likely to be incorrectly set - that is - unless someone else has been at them before.

As a crude test - try spacing the master cylinder away from the firewall with a couple of washers - if that doesn't change anything - lack of free play is a symptom and not the cause.
Title: Re: Brakes locked up!! HELP
Post by: talonxracer on March 11, 2012, 06:14:46 AM
Freeplay usually has an adjustment within the brake booster, I have seen malfunctioning brake boosters keep pressure upon the brake system as well.
Title: Re: Brakes locked up!! HELP
Post by: g35-coop on March 11, 2012, 08:14:29 AM
Could it be the proportioning valve?
Title: Re: Brakes locked up!! HELP
Post by: fordem on March 11, 2012, 09:32:37 AM
Could it be the proportioning valve?

Shouldn't be - the proportioning valve has very little effect on the front brake - although - it does need to be properly bled - the bleed nipple on it connects to the front brake circuits.

In other words - it can make them spongy if air is trapped - but should not create the situation you describe.
Title: Re: Brakes locked up!! HELP
Post by: g35-coop on March 12, 2012, 08:41:52 PM
Well I think I'm going to try a new master cylinder and if that isnt the problem then at least I have a new one haha.
Title: Re: Brakes locked up!! HELP
Post by: mrfuelish on March 12, 2012, 09:45:16 PM
If your master was no good or leaking you would not have the problem that you have!
Title: Re: Brakes locked up!! HELP
Post by: fordem on March 13, 2012, 05:32:30 AM
If your master was no good or leaking you would not have the problem that you have!

If I was closer to you, I'd offer to come over and prove you wrong - granted a leak or worn seals won't cause the problem, but a plugged relief port or swollen seals most certainly can.
Title: Re: Brakes locked up!! HELP
Post by: talonxracer on March 13, 2012, 06:11:21 AM
Depress the brake pedal and get the calipers to clamp and lock up and then start cracking open the brake lines from the calipers back to the master cylinder untill the blockage is revealed.
Title: Re: Brakes locked up!! HELP
Post by: fordem on March 13, 2012, 10:24:38 AM
Which lines did you change?

I just took a look at the Samurai EPC and noticed there are two flex lines hoses between the master cylinder and a "6 way" joint on the frame rail - basically they are there to allow for movement between the body (where the master cylinder is mounted) and the frame - defective flex lines are known to cause issues like this.
Title: Re: Brakes locked up!! HELP
Post by: mrfuelish on March 13, 2012, 06:06:02 PM
to narrow down the problem with out replacing everything, Whats wrong with taking the nuts off of the master and pulling it forward to see if it helps? it's cheap and helps to narrow things down a little. I have seen cleaning solvent and all kinds of things that people put in things that don't belong there but with what little info you get on the history!
Title: Re: Brakes locked up!! HELP
Post by: g35-coop on March 16, 2012, 06:48:38 AM
I broke the brake lines loose at the master cylinder to see if it would relieve the pressure and it worked so that was why I was going to change the MC.  There are zero leaks in the lines.  I broke the two lines at the MC and the front line made the passenger side turn with no problem and the line towards the back of the MC let the driver side loose.  I don't do brakes so I'm at a dead stop with this thing.
Title: Re: Brakes locked up!! HELP
Post by: talonxracer on March 16, 2012, 07:31:12 AM
Power brakes correct? it will be the MC or the brake booster. try disconnecting the brake boosters vacuum line(plug the line after removing) and see if the brakes lock and unlock.
Title: Re: Brakes locked up!! HELP
Post by: mrfuelish on March 16, 2012, 11:07:40 AM
Yep, the brakes on a sammie work in an X pattern, left front and right rear same line on master, right front and left rear are on the same line on master. on the older ones with two brake lines on the rear diff.