TR2/3/3A TR3A Brake distribution block

[TFR]

Does anyone know what function the brake block performs? Having issues with the car pulling to the left while braking and have replaced all brake components on both sides. Wondering about the blocks function to see if it might have an effect on this condition.

 

[Moseso]

There are two of them: One at the front, and one at the rear.
Easier first. The one at the rear is a simple "T". Fluid in on leg and out the other two -- to the right and left rear cylinders.

The one in front is only a little more complex. Fluid in one leg and out the other four: Right & left front brakes, the brake light switch and the the pipe to the rear tee. There is no provision for valving or pressure differential -- except -- there is an anti-return valve on the input leg that keeps the whole system slightly pressurized. It's supposed to prevent the front disc pistons from being pushed too far back into their bores. It does cause a slight amount of brake drag. Some people remove it. I did. My brakes work just fine without it.

All that said, it's unlikely that your pull to one side is being caused at either of these pipe unions. I would look for leaks and freedom of movement at each wheel as step-one. If you got fluid at each corner when you bled your brakes, the pipes/unions are not clogged. It would take an unusually large piece of gunk to clog the output on one of those unions.

 

[TFR]

Everything in the brake system is either rebuilt or new. So I don't think it is the lines or hoses.
After I posted this question I finally found a explanation for the relief valve. I thought it might be a place that might cause my situation.
I am truely at a lose.

 

[Don Elliott]

The Haynes Manual for TRs shows how to assemble the innards. Just like my sketch and photo. BTW it's called a restrictor valve. You can search for more in the archives using "restrictor valve".

 

[TR3driver]

I once bought a TR3A that pulled hard to the left under braking ... problem turned out not to be the brakes at all but one of the front inner suspension pivots had pulled loose from the frame. Even the alignment shop didn't spot the problem, because it returned to approximately the correct position when not braking.

But when the brakes were applied, the pivot would move and cause the wheel on that side to turn to the side, just as though the steering wheel had been turned.

 

[Don Elliott]

I heard about a TR owner in England who had his brakes pulling on one side and not on the other. Much later, he found he had a small leak in the short rubber brake hose on one side and when he turned the steering whell, the hose would flex, the hole would open and he would lose some fluid. When he stopped and lifted the TR, there was no brake fluid coming out, nor could he spot any on his garage floor. It leaked only when he was turning. Finally he changed his hoses. I know this is not your case if you changed them recently on your TR but I thought you might like to know how small gremlins which are hard to find can make things dangerous.

Another TR3A chap in England replaced his brake pads for the front and found they braked about 50% compared to his former old ones. So he put in one of the old pair of pads on one side and during this test, he found that the side with the old (good) pads braked as before pulling him over to that side. He proved that "new" pads may not be as good as what you had in there before. Maybe one of your new pads has inferior lining material doing this.

Try your old pads back in and re-test.

 

[TR3driver]

Maybe one of your new pads has inferior lining material doing this.

Or pads that got contaminated somehow. One way they can get contaminated is an unnoticed greasy fingerprint left on the rotor surface while installing the hub.

Not that I've ever done that, of course.

 

[Geo Hahn]

Simple thing but just in case you haven't checked it -- low pressure in one front tire can cause a pull. Sometimes hard to tell by just looking at radials.

 

[TFR]

The lower pivot mounts were broken when I restored the car. Perhaps the welds have failed. Good one to check. This will happen today.
What's the best way other then visual?

Thanks for all the input..

 

[bgbassplyr]

Apply the brakes. If car pulls to one side.........lol

 

[TR3driver]

What's the best way other then visual?

Find some way to pry on them and see if they move. Sorry, it's been way too long for me to recall the details, but I found some way to jam a big pry bar in there.

Another method might be to have someone turn the steering wheel against the stops at both sides, and see if that produces any unusual movement in the suspension.

 

[TFR]

Hurray! After further investigation, due to your input, I have discovered the problem. Like a couple of you stated the pivot uprights on the driver side were cracked. It was obvious after I put a light on the area.
I clamped the broken parts into place and rewelded them. Seems to have helped a lot. It still pulls a slight amount but I think I will have to have the alignment checked. Might need to bend the pivot bottm forward.

Anyway, thanks a bunch for all your postings and suggestions. AGAIN outstanding sight!

 

[Moseso]

That's the beauty of this place. If it's happened to a TR, it's been seen by somebody here.