11 replies to this topic

[Syma]

Hoping someone here can help me. I am nearing the end of the restoration and I started adding brake fluid and bleeding the lines. I have a dual master cylinder and the front seams to work fine but I am getting no fluid out of the top port for the rear lines. I even took off the line to see is anything is coming out when I pump the brake. The cylinder is the original but we did use a repair kit. I am almost 100% sure we put it back together correctly but I am just not sure why I would only be getting fluid out of one port. Any help would be great.

thanks

[nicklouse]

sounds like it is working just fine if you are pressing hard on the pedal as it thinks there is a leak and is closing of the rear circuit.

 

slow low pressure pedal movement. or just open the ports and let it drain through.

 

and bleed in the order as stated in your Haynes manual. Normally start at the furthermost one from the MC.

[Syma]

sounds like it is working just fine if you are pressing hard on the pedal as it thinks there is a leak and is closing of the rear circuit.

 

slow low pressure pedal movement. or just open the ports and let it drain through.

 

and bleed in the order as stated in your Haynes manual. Normally start at the furthermost one from the MC.

 

Open what ports? The bleed valve? 

[nicklouse]

yep.

[Spider]

In reassembling the MC with new seals etc, there is one seal for the upper piston that is fitted in a reverse way to the others. If you've fitted this the wrong way (ie, same as the others) this circuit won't work.

[Syma]

In reassembling the MC with new seals etc, there is one seal for the upper piston that is fitted in a reverse way to the others. If you've fitted this the wrong way (ie, same as the others) this circuit won't work.

sounds like I need to drain it and take it out of the car. On a side note when I got mine it had the original brake lines and the rear brakes were plumbed to the top port of the master cylinder but I keep reading that it is backwards. 

[Syma]

I have read that since mine is not a stepped bore then it doesn't matter if the top is the front or rear. The yellow tag ones that have two different size threads need to top one to be the front. 

I think thats right

[Spider]

 

In reassembling the MC with new seals etc, there is one seal for the upper piston that is fitted in a reverse way to the others. If you've fitted this the wrong way (ie, same as the others) this circuit won't work.

sounds like I need to drain it and take it out of the car. On a side note when I got mine it had the original brake lines and the rear brakes were plumbed to the top port of the master cylinder but I keep reading that it is backwards. 

 

 

I'm guessing this was a Green Tag MC?  It had a Brake Fail switch in the main body of it and a large hex bolt head in the top of it?

 

If so, then that is plumbed correct.

[Syma]

Well I took the master cylinder out of the car, took it completely apart  and gave it a really good clean. I checked, checked again and checked a few more times to make sure I had all the components in the correct order. I put it all back together, bench bleed it and put it back in the car and still the port for the front brakes works great but nothing comes out of the top port. When I bench bled it I did get bubbles out of both ports so I am now at a loss. There is no break fail switch either. Maybe one of the parts from the repair kit are defective but I don't think I have any other option but to buy a new one. 

[Spider]

Post 13 in this thread has an exploded diagram of the Green Tag Master Cylinder if that's any help;-

 

http://www.theminifo...ag-how-install/

 

There was another much earlier type again, it had a rather large lid on it, but weren't fitted to many cars.

[Syma]

I used that exploded diagram, hanse manual and the instructions from my repair. Thanks for your help. On a plus side I now know more about how the master cylinder works and all the different types.

[tiger99]

Is the pedal returning fully? If not, the reservoir port may not be uncovered properly, which will not let fluid in to whichever part of the cylinder is affected. The pedal should be hanging on the push rod and the return spring must be intact.

 

If it is s non-servo system, Somerford Mini have shims that go under the master cylinder to make small adjustments if there is a tolerance buildup on the pedal etc. They come in two halves so can be fitted without undoing the hated clevis pin.