Brake bleeding issues

fin170703 · Post by **fin170703** » Thu Aug 04, 16 11:44 am

pulled the collar clean out, and it just had a little plunger on it, not something I would imagine would reset anything ! didn't make any difference

Would it be a different part on the junction ?

fin170703 · Post by **fin170703** » Thu Aug 04, 16 11:46 am

Dave999 wrote:anything without a pipe
but looks like it might have had a wire to it

basically the metal piston when locked in the Block off a circuit position
also earths the wire from the dash light and makes it come on

so a lump for a connector and a switch is 99% of the time the one you want

the piston is dumbbell shaped when it shuttles to one end the fat bit at that end blocks off the circuit and the fat bit at the other end gets locked by the end of the switch so it stays in poistion

Dave

I'm thinking the big nut on the front ?

fin170703 · Post by **fin170703** » Thu Aug 04, 16 12:17 pm

Ive pulled the valve and the piston is seized solid with rust

I'm going to free it all off and re attach, see if that sorts the issue

Post by **MattH** » Thu Aug 04, 16 12:22 pm

Ah, I remember all this fun myself now!! I did away with the distribution block low pressure thing and just put a Triumph style connector in as I could not get the brakes to bleed either.

Dave999 helped me through it and explained the workings of the block of trouble.
Matt

fin170703 · Post by **fin170703** » Thu Aug 04, 16 12:25 pm

Matt ive thrown a few Bananarama! around this morning, I can tell you :-)

fin170703 · Post by **fin170703** » Thu Aug 04, 16 12:32 pm

piston is all freed off now, and moving as it should as the pressure is put on the pedal, but still a solid pedal, as if the rear brake part is blocked by something

I'm pretty sure its the proportional valve. I've undone the nut but the rod seems to be stuck inside

I'm going to strip the unit out and give everything a good clean

Dave999 · Post by **Dave999** » Thu Aug 04, 16 1:33 pm

id suggest that a proportioning valve is a good thing. the rears are easy to lock up without

but they can also get blocked

springs shims piston thing and a tiny hole from what I remember

Dave

Pete · Post by **Pete** » Thu Aug 04, 16 1:36 pm

I thought you had to depress that pin to get the rears to bleed - many moons ago when I did it....

fin170703 · Post by **fin170703** » Thu Aug 04, 16 2:02 pm

Ive stripped the whole thing off and the piston seemed to be jammed in the 'up' position, and was difficult to free off. managed to pull it out eventually so I'm hoping this is the issue.....everything looks clean and tidy so I'm going to put it all back together and see if the b*gger works

I did think of that Pete, slackening off the proportional valve to bleed, but wasn't sure if it would draw air in.

Pete · Post by **Pete** » Thu Aug 04, 16 2:21 pm

On the lower unit the pin is facing forwards and that should depress - I have used a clamp on one in the past.

fin170703 · Post by **fin170703** » Thu Aug 04, 16 2:35 pm

I did read something about holding the pin out, on the front valve, but I think that's to do with the front brake

My issues seem to be with the rear proportioning valve.

Learning as I go here

but fingers crossed, it'll work now I've freed off the piston on the proportional valve.

Ive had enough for one day, I'm going to whack it back in tomorrow

fin170703 · Post by **fin170703** » Thu Aug 04, 16 2:45 pm

So this diagram shows my Distribution unit. When I drop the nut and spring from the Proportional valve, the plunger was stuck up inside the bore... im really not sure if this is my issue as the piston is hollow, and looks like the fluid should flow up through it when the chamber is full anyway!?

I'll bolt it back up and see

fin170703 · Post by **fin170703** » Fri Aug 05, 16 10:28 am

I'm trying to work out how the proportional valve works.

Does the rear part of the system require constant pressure to keep the spring compressed / piston in the down postion ?

As it stands, the distribution block is out and the proportional valve is assembled. if I blow through the rear brake inlet, its all blocked off as the spring is pushing the piston up, thus blocking the flow.

So if I now install the block into the car and try and bleed the brakes, do I need to slacken the valve right off to bleed ? As I cant see how the piston will allow flow, without pressure !!!!!

This is driving me insane !!!!!

Pete · Post by **Pete** » Fri Aug 05, 16 10:51 am

That diagram is in the static position - I would guess that the shuttle has moved forward thus blocking the port.

This is why I said about pushing the pin in to re-position the shuttle.

fin170703 · Post by **fin170703** » Fri Aug 05, 16 11:40 am

It isn't blocking the port pete as if I put my thumb over the proportional valve (with the inners removed) the air flows through just fine

Now when I put the valve assembly back, and do it all up, obviously the spring is pushing the piston back up, blocking the hole. The only way I can see it allowing fluid through is with back pressure.....