TR6 Can't seem to bleed TR6 brakes

[zmayne]

Hey all,
I wanted to know if anyone had any special techniques they could share to bleed TR6 brakes. I have a new master cylinder/reservoir, rebuilt front calipers and braided steel brake lines (and recent pads and drilled rotors). I get a strong stream of brake fluid out of the calipers, but keep on getting air bubbles. We are bleeding from the left front, to the right, then the right rear to the left rear. I can't seem to bleed them to get a nice, hard pedal. The pedal feels very soft until you pump the brakes, and then travel is still about half way down the full pedal travel. The car stops, but the brakes are not very confidence inspiring. I also can hear a slight "puffing" (for lack of a better word) from the brake booster or that area. Anyone know what a bad brake booster feels like? Could that even be the problem? Help!!
Thanks,
Zach

 

[PeterK]

Usually it's best to bleed the farthest brake first i.e the right rear, then work your way forward. Some bench bleed the TR6 m/c berfore installing it.

 

[Gliderman8]

Are you continuing to monitor the fluid resivoir and add additional fluid as needed?
If you let it run out, you will get more air in the lines.
And yes... I am in agreement... start at the RR wheel, the one FARTHEST away.

 

[Andrew Mace]

According to Girling (from a Tech. bulletin reprinted in a 1964 issue of TSOA News), cars with front disc and rear drums should be bled starting with the left front. The caveat here is that the bulletin information all references the older single-circuit master cylinder. Perhaps it could be different with a dual-circuit master?

I also agree with others here that, with the dual-circuit M/C, it seems almost mandatory to bench-bleed that first.

I have to wonder if you are sucking air in somewhere during the bleeding process?

 

[hondo402000]

also if you have one of those vacuum bleed units it does a good job of bleeding brakes and you can check your servo with it, if the servo wont hold a vacuum it has a hole in it. Plus inside the servo there is a screw with a round ball on the end and a locking nut that adjust outward and makes contact with the MC plunger, I think the clearance was somewhere around .010, I just kept screwing it out 1/4 turn till the breaks felt right(if the servo was not replaced it might be fine), you can turn it too far out and the pressure wont bleed off after you press the brakes, I got mine so tight it eventually locked the brakes up and had to carry wrenchs around while driving while I was adjusting it, Drive, test, adjust, repeat

Hondo

 

[Geo Hahn]

Note: The following comments are based on my experience with 4 cyl TRs and may or may not apply to the TR6...

If you think you need to bench bleed you might get away with doing this... crack the output connection on the MC just a bit so the line is loose. I put a couple of drops of brake fluid on the fitting first -- that way I can watch little bubbles as the MC fills (by gravity) and air works its way out. Once the bubbles stop, tighten the fitting.

I have always thought it was 'start with the farthest bleeder' though on TR3s and 4s that is the left rear (even though the MC is nearer the left side the brake lines go over to the right front for distribution and the rear split is at the RR (since these cars were designed as RHD).

I may try Andy's (well, Girling's) method next time though given how those splitters are set up I doubt it makes much difference.

 

[Dale]

I've had problems in the past with air leaking at the threads on th ebleeder valves as well as at where the hose from the vacuum bleeder slips over the valve. All this is behind me since I got "Speed Bleeders". I actually look forward to bleeding the brakes on my Healey and TR7 now. I'm sure y'all are sick of my testimonials about them, but doggone it; they work.

 

[Tr4dude]

Since most of my work is done by myself I found after the MC starts pumping and is bled, starting from the rear put a clear hose over the bleeder into a bottle/ catch pan and crack each bleeder one at a time and let gravity do the work, always keeping a watchful eye on the MC level, watch the tube and after you see no bubble going through the clear hose tighten the bleeder screw and move to the next one. IMPORTANT: When you are done double check every connecter in the system to make sure they are tight. Do not reuse fluid that has gone through the system and brake fluid is cheap so the more you let it drain the better the system will be flushed out. This method has not failed me yet. If you are not using Dot 5 or synthetic fluid it is better to bench bleed the MC to help avoid getting alot of fluid on the paint.

 

[HerronScott]

I have always thought it was 'start with the farthest bleeder'

That's the way that I was taught as well. With split systems I still did the same but treated front and rear independently.

Scott

 

[Andrew Mace]

I have always thought it was 'start with the farthest bleeder' though on TR3s and 4s that is the left rear (even though the MC is nearer the left side the brake lines go over to the right front for distribution and the rear split is at the RR (since these cars were designed as RHD).

I may try Andy's (well, Girling's) method next time though given how those splitters are set up I doubt it makes much difference.

Since I "started" this, I'll try to finish it by saying that, apparently, Triumph was of the "farthest first" philosophy as well: first back, then front circuit. This according to my Bentley Manual. Live and (re)learn.... :laugh:

 

[HerronScott]

Since I "started" this, I'll try to finish it by saying that, apparently, Triumph was of the "farthest first" philosophy as well: first back, then front circuit. This according to my Bentley Manual. Live and (re)learn.... :laugh:

That's probably where I learned it since I learned everything about car maintenance from my Bentley manual.

Scott