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nick Avatar
nick nick m
Bend, OR, USA   USA
After the car sits for awhile I get a brake warning light. The fluid is topped up and the brake pedal is firm. After driving for about 10 min the light goes out. I though it might be air in the master. I have a bleeder on the master but am not sure what the bleeding procedure is. I did open it and pressed on the pedal but almost no fluid comes out but the light goes out. I have done this twice. Today, after not using the car for about 4 days I found the pedal soft to the floor. I again tried to bleed the master but no fluid came out after 70 pedal pushes. Next I will try to bleed it from the rear brake. Any suggestion on what this could be?



nick

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kansanbrit Avatar
kansanbrit Phil H
Bonner Springs, KS, USA   USA
1952 MG D-Type Midget
1964 Morris Mini-Minor
1980 Triumph TR8
1980 Triumph TR8 "TR8 Holley"    & more
If no fluid comes out with bleed valve open then maybe your flexible brake hose has collapsed inside...

nick Avatar
nick nick m
Bend, OR, USA   USA
I bled the rear and no bubbles. The right front had quite a bit of air. Nothing much out of the left front. But now they are firm again. But the mystery is how does this happen? The brakes were working perfectly before my description of the sequence in the original post. I do recall from another event (not a TR7/8) where the master kept introducing air into the system and the brakes were soft until the master was replaced.



nick

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Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, OR, USA   USA
1980 Triumph TR8 "Wedgie"
In reply to # 1502756 by nick I bled the rear and no bubbles. The right front had quite a bit of air. Nothing much out of the left front. But now they are firm again. But the mystery is how does this happen? The brakes were working perfectly before my description of the sequence in the original post. I do recall from another event (not a TR7/8) where the master kept introducing air into the system and the brakes were soft until the master was replaced.

With the car level, cracking open a front bleed nipple should result in a steady trickle of brake fluid if everything is up to snuff. In other words you should be able to gravity bleed the front brakes. If not, suspect a bad brake line or clogged pressure reducing valve.

My original pressure reducing valve was full of something that looked like cooked oatmeal. No idea what it was. After cleaning and replacing the seals, I went to reinstall it and pulled out the threads on one of the orifices while snugging down the fitting. It must have been overtightened at some point in the past. <sigh> Replaced it with a new one. Front brakes gravity bleed very nicely.

My point is that after 40 years, who knows what evil lurks inside your brake system. If you can't gravity bleed the fronts, something is clogged.

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore

TR8todd Avatar
TR8todd Todd Kishbach
Mass, USA   USA
1977 Triumph TR7 "Rally Fraud"
1978 Triumph TR8
1979 Triumph TR7
1980 Triumph TR8    & more
Willing to bet the master is leaking and the booster is slowly filling up with fluid.

nick Avatar
nick nick m
Bend, OR, USA   USA
In reply to # 1502797 by TR8todd Willing to bet the master is leaking and the booster is slowly filling up with fluid.

Uh oh. Found a drop of fluid on the boot above the pedal. I had not considered the master leaking since it is only about 4 years old. Looks like I'm in for a new one. Or should I attempt a rebuild?

Is there a way to drain the master in the event it does have fluid in it?

I have a bleed port on the master cylinder. What is the correct procedure for bleeding it?



nick



Edited 1 time(s). Last edit at 2017-12-15 12:31 PM by nick.

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