Jthompson1

Hey guys I'm new to the whole thread community, I traded for a beautiful Gs430.... but there is the kicker.... I'm getting absoultley zero pressure to both calipers in the rear I've checked all the fuses and relays they're all intact, the fluid is clean, there are no leaks. Ive already tried bleeding the calipers, and there is fluid getting to the caliper but nothing coming through the caliper. Bled each side for about 30 minutes here is the question I need help if anyone has had the same problem and what some troubleshooting steps and links for replacement parts. Thanks in advance guys

Mr Jokster

iTrader: (8)

Well considering you checked all the fuses LoL

Seriously though, seems to possibly be the worst case scenario which would be seized calipers. If you see fluid escaping while bleeding them, i would assume that the pistons are stuck. However, its hard to believe that it would happen to both calipers at the same time.

Oh, other question... How do you know you've got no pressure back there? You stated you can bleed them, which means pressure IS going back there.

GS400V8

iTrader: (4)

How do you know there is no pressure? The brake pedal is still soft?
When the ABS pump cycles it might have air in it thus rendering your brakes useless. There is a complicated ABS pump bleed procedure.

Also, everyone bleeds different and they are not always equal
I always use some type of bottle filled with clean brake fluid, and submerge the 3/8" clear tubing into the fluid before cracking the bleeder screw on the caliper. I also use a zip tie on the clear tubing around the bleeder screw. This ensures that no air will come back up into the lines like is possible when you put the clear tubing into a bottle full of air with no fluid and let it bleed that way. The zip tie ensures the line won't pop off and completely undo all your work and possibly cause a lot of headaches.

I've also used this method and have had no problem on my car or my previous one

Jthompson1

Essentially what's going on is is there is no pressure going through the caliper in order to compress the piston in the caliper what I did was as I took the caliper off the bracket took the bleeder valve completely out turned it upside down and it would only drip about maybe one drip every couple seconds so there's some fluid escaping the caliper but when you press the pedal there is absolutely zero pressure going through the caliper an through the bleeder valve I've tried testing the motor just by Crossing it over completely just to see if it would kick on and there's nothing so my fear is that the pump went out but I have no way to check I've read that there is a anti-lock brake pressure switch I don't know if that may do it but it's throwing about 11 different ABS codes for a valve being stuck open and everything else not working so I'm trying to figure out troubleshooting steps to figure out what is actually bad

Jthompson1

What's going on is this when I'm driving the pedal is super super stiff and really hard because it's only using the front brakes there is no caliper compressing there's no brake pressure at all in the rear

GS400V8

iTrader: (4)

It looks like if you didn't even use tubing to bleed them, you definitely have air in your ABS system. You need to re-bleed them the correct way first or take it in to a shop. Hopefully you don't have to get a new ABS unit

LexLova

got one one for sale from 02 122k mi

Jthompson1

I'm definitely going to find someone that can bleed them appropriately, thank you guys for the help, and lex if the bleeding doesn't work I'll pm you for pricing and shipping on your unit for sale

burteboy

You need to check your booster. Sounds like the booster is not functioning or you have a vacuum leak. Disconnect the hose to your booster and check for vacuum .