mk1-forum.net

Hello,

I know there was a thread on a similar topic recently which I have read and haven't found a solution. The problem is that the brake master cylinder will not prime at all. It is the tin lockheed type which I believe is original in my 66. I have taken out the brake line from the top to see whats happening and there is no action at all. I have tried pouring a little fluid into the hole and it drains back into the reservoir when the pedal is pumped. The reservoir is pretty full but not brimmed. I have read that it helps to fill it very high. The clevis pin is in and its all attached. The cylinder came out of the car about 2 months ago and has been dry stored. It worked just fine before I took it out. It hasn't even been long enough to dry out. It still was wet with fluid inside so I'd be surprised if any seals had dried out.

Before I attempt a rebuild or I buy a new one has anyone got some good tips for priming and bleeding the brake master. Or anything I should check to determine if its gone bad. Thanks,

Daniel

With the brake pipe off, get someone to pump (fast using a hand, not foot) and tell you each time the pedal hits the floor,
you follow him/her? with the same speed, and put your finger over the top, to seal the hole for the brakepipe, each time, the pedal goes back up,
and then you remove your finger, when it when its pressed down again.
Its becourse it sucks air in, that it wont prime.
This always get them going for me.




Jens Christian

I thought it might be something like this. To be honest it was getting late in the day and I was already discouraged after I found a hydrolastic split and the engine wouldn't fire. I will give it another go. Thanks,

Daniel

I ended up putting on the easy bleed to it AND pumping the pedal but used the first pipe from the cylinder into a jar of fluid. 2 man job really but it worked.

What can happen is that old MCs will not reseal to bleed after draining the system. 1st option is an Easibleed, 2nd is replace the rubber seals.

JC T ONE wrote:With the brake pipe off, get someone to pump (fast using a hand, not foot) and tell you each time the pedal hits the floor,
you follow him/her? with the same speed, and put your finger over the top, to seal the hole for the brakepipe, each time, the pedal goes back up,
and then you remove your finger, when it when its pressed down again.
Its becourse it sucks air in, that it wont prime.
This always get them going for me.




Jens Christian

I had to do exactly this to get mine to prime.