S-PAutomotive.com

Author Topic: Brakes wits end  (Read 2644 times)

May 01, 2018, 09:28:33 pm

TBrooksy

  • Newbie

  • Offline
  • *

  • 1
Brakes wits end
« on: May 01, 2018, 09:28:33 pm »
G'day all,

I'm new to car stuff and I'm learning as I go, so please forgive me and bear with me as I'm quite stuck.
I have a barn find 86 Golf that I'm at my wits' end about the brake system. Here's the run down

the 1.6 n/a engine was rebuilt 100,000 km ago with components from an 87; when purchased the brakes were quite spongey.

I replaced the master cylinder, bled lines at master and at the calipers with new brake fluid, and the brakes immeadiately showed improvement.

However, I started to experiance smoking brakes and brake drag. Rolling smoke off the front brakes! wheels hot to the touch!

Upon review from a licensed mechanic he said the brakes were seized, he free/cleaned everything up, and recommended I replace cracked flexible lines.

Flex lines and fittings were replaced. no change in brake drag.

Replaced calipers, rotors, and pads with new parts. bled lines again. brake drag persists.

I dismanteled the master cylinder to inspect it; it functions well, is clean and shiny.

I flashed a light inside the vaccuum brake booster to check its condition, it's corrosion free and functions well.

It appears that the brake booster is linked to some sort of vaccuum pump and check valve at the front of the engine. Is that normal??

Could this problem lead back to a failing vaccuum pump? could the vaccuum pump from an 87 have more pressure than that of an 86? Could the brake fluid reseviour cap somehow impead brake disengagement? could I have a faulty master?

I have attached a couple photos showing the location of the vaccuum pump and wear on the new rotors. I'm lost and loosing hair. If there's anyone out there who might be able to shine a light of hope my way please do. Thanks in advance,

-Brooksy






Reply #1May 01, 2018, 10:53:07 pm

ORCoaster

  • Moderator
  • Veteran

  • Offline
  • ***

  • 4383
  • Personal Text
    Restoring a Caddy as time and weather allows
Re: Brakes wits end
« Reply #1 on: May 01, 2018, 10:53:07 pm »
Brooksy,  Welcome to the My brakes are messed up club.  Here is what I read from your message.

New Master cylinder and all new parts at the wheels so how come they drag.  You get a good vacuum off that style of pump and the check valve keeps the booster full for ready use.  So what might be the problem?  The little rod that is in the back of the master cylinder is keeping pressure on the booster and keeping the brakes on. 

Turn it so it becomes shorter and reattach to the MC.

I would also suggest that you visually inspect the lines for a crimp or a sharp bend.  These cars do not always get jacked up on the pads behind the front wheels and the lines get smashed.  Especially by sliding a floor jack under there without checking where it will be lifting. 

Check the lines to the back as well.  You didn't say if you did any work on them but I would be jacking up the car and spinning those wheels by hand and have someone step on the brake.  You may be only using the two front ones to stop the vehicle.  Happened to mine.  That is due to the 8 year sit that it had.  Previous owners put new brakes on it but they seized up with rust due to no use.

So check those items and let us know if things are stopping for you better and you are running cooler discs.

Reply #2May 07, 2018, 01:26:32 pm

srgtlord

  • Veteran

  • Offline
  • ***

  • 791
Re: Brakes wits end
« Reply #2 on: May 07, 2018, 01:26:32 pm »
Did you replace the caliper slide pins? I know I have had a similar issue where the slide pins rusted preventing the caliper from moving correctly