Brake Lines Clogged

PoochyCor · 07-13-2007

On a '64 Kadett (A) I've replaced with NOS the master cylinder and front wheel cylinders and rebuilt the rear cylinders. Fluid bleeds through both front bleed valves but neither rear cylinders

. I disconnected the brake line at the rear axle (where it splits to go to the wheels) and no fluid. The brakes were completely dry when I started and had been for years.

I assume I have a clogged line. Make sense?

What are the chances that I can blow it out with compressed air (about 90 psi is all my compressor will muster)?

BQS4 · 07-13-2007

Originally Posted by PoochyCor

What are the chances that I can blow it out with compressed air (about 90 psi is all my compressor will muster)?

Give it a try, can't be any worse than what you have now, except that it might blow out the obstruction.

kwilford · 07-13-2007

The obvious question is "Have you replaced the flex hoses"? It's a well documented fact that old flex hoses collapse internally and can either restrict the flow of fluid, act like a "check valve" and not allow brakes to release, or even completely block ANY flow of fluid.

And your compressor at 90 psi is not even close to the brake fluid pressure exerted by the master cylinder, which I believe is in the order of several hundred to as much as 500 psi (even more in modern brake systems).

HTH

namba209 · 07-14-2007

I would try and disconnect the rear brake hose from the line and see if you get fluiid out of the line. That would take the rear hose out of the equation, and confirm or deny a blockage from the MC to that point, anyway. Then you can check out the hose, if it's bad just replace it and go for bleeding the rear brakes. HTH.

PoochyCor · 07-14-2007

I replaced the flex hoses up front but it is metal all the way to the wheel cylinder in the rear.

kwilford · 07-14-2007

Originally Posted by PoochyCor

I replaced the flex hoses up front but it is metal all the way to the wheel cylinder in the rear.

Hmm, I have never seen a '64 Kadett let alone worked on the brakes on one. But I assume it has a "live" rear axle, and therefore it must move up and down. On every car I have ever seen with a live rear axle, there is a flexible hose connecting the steel brake lines attached to the body with the steel brake lines attached to the differential. Have another look just to humour me. On the later Opels, it is just in front of the differential, near the centre line, slightly towards the driver's side.

PoochyCor · 07-14-2007

I LOVE this website! - and feel a little stupid

(not an unfamiliar feeling) Sure enough, there is a very weathered looking hose on the front side of the differential. I'll replace it and see what I get. That'll be next weekend, we're headed to a family reunion a couple of states over today.

THANKS!!!

07-13-2007	#1 (permalink)
PoochyCor Type "A" Join Date: Jun 2006 Location: Oklahoma Posts: 83	Unanswered: Brake Lines Clogged On a '64 Kadett (A) I've replaced with NOS the master cylinder and front wheel cylinders and rebuilt the rear cylinders. Fluid bleeds through both front bleed valves but neither rear cylinders. I disconnected the brake line at the rear axle (where it splits to go to the wheels) and no fluid. The brakes were completely dry when I started and had been for years. I assume I have a clogged line. Make sense? What are the chances that I can blow it out with compressed air (about 90 psi is all my compressor will muster)?

07-13-2007	#3 (permalink)
kwilford Über OpelGT.com Moderator Join Date: Mar 2002 Location: Calgary, Alberta, Canada Posts: 4,087 Real Name: Keith Wilford Provided Answers: 4	The obvious question is "Have you replaced the flex hoses"? It's a well documented fact that old flex hoses collapse internally and can either restrict the flow of fluid, act like a "check valve" and not allow brakes to release, or even completely block ANY flow of fluid. And your compressor at 90 psi is not even close to the brake fluid pressure exerted by the master cylinder, which I believe is in the order of several hundred to as much as 500 psi (even more in modern brake systems). HTH __________________ Keith Wilford working on my '71 GT and '75 SportWagon

07-14-2007	#4 (permalink)
namba209 6,000 Post Club Join Date: Aug 2002 Location: Imperial Beach, CA South of San Diego Posts: 6,054 Provided Answers: 6	I would try and disconnect the rear brake hose from the line and see if you get fluiid out of the line. That would take the rear hose out of the equation, and confirm or deny a blockage from the MC to that point, anyway. Then you can check out the hose, if it's bad just replace it and go for bleeding the rear brakes. HTH. __________________ Ron 72 GT 3.4L V-6/T-5/ZF posi - almost done - Just need AC installed. 75 Chevy monza 5.7L/TH350/Auburn 3.08 posi - Next

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07-14-2007	#5 (permalink)
PoochyCor Type "A" Join Date: Jun 2006 Location: Oklahoma Posts: 83	I replaced the flex hoses up front but it is metal all the way to the wheel cylinder in the rear.

07-14-2007	#7 (permalink)
PoochyCor Type "A" Join Date: Jun 2006 Location: Oklahoma Posts: 83	I LOVE this website! - and feel a little stupid (not an unfamiliar feeling) Sure enough, there is a very weathered looking hose on the front side of the differential. I'll replace it and see what I get. That'll be next weekend, we're headed to a family reunion a couple of states over today. THANKS!!!

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