Replacement master cylinder questions
Thread Starter
Heel & Toe
Joined: Nov 2011
Posts: 15
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Replacement master cylinder questions
Hi there - I am about to overtake a full overhaul of my braking system on my 81 tomorrow. I have purchased one of those shiny new master cylinders, new stainless braided brake lines and new o-ring calipers and a set of new pads.
I have a a couple questions about the particular M/S.
It's one of those:
The first obvious difference is that it has 4 ports rather than the 2 of the one I am replacing. It came with 4 yellow caps but I have blocked the 2 rear ports with correct thread bolts.
First question: When I bench bled it i only did on the 2 ports I am planning to connect the lines to. Should I have bench bled the other 2 ports as well?
Second question: I realised that this is slightly incorrect bore for my power brake equipped vet. It is 1'' bore which is correct for manuals rather than the 1 1/8'' which should be the one for power brakes. I have read that this should lead to a slightly longer travel distance for the pedal. Does anyone know how much longer roughly it should be and whether any other issues might arise?
I have a a couple questions about the particular M/S.
It's one of those:
The first obvious difference is that it has 4 ports rather than the 2 of the one I am replacing. It came with 4 yellow caps but I have blocked the 2 rear ports with correct thread bolts.
First question: When I bench bled it i only did on the 2 ports I am planning to connect the lines to. Should I have bench bled the other 2 ports as well?
Second question: I realised that this is slightly incorrect bore for my power brake equipped vet. It is 1'' bore which is correct for manuals rather than the 1 1/8'' which should be the one for power brakes. I have read that this should lead to a slightly longer travel distance for the pedal. Does anyone know how much longer roughly it should be and whether any other issues might arise?
Thread Starter
Heel & Toe
Joined: Nov 2011
Posts: 15
Likes: 0
Also - I would be interested to know as to whether the I should start the bleeding process with the rear left caliper (as in my Haynes manual) or with the rear right - which is the furthest away from the master cylinder? Many thanks!
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
I think you want to keep one side of your MC capped off. This is for different applications.
Be sure to bench bleed the master before installing and adjust the pushrod correctly !
Bleeding the rest of the system I would purchase a power bleeder. Its worth it and I wish I would have when I did mine
Be sure to bench bleed the master before installing and adjust the pushrod correctly !
Bleeding the rest of the system I would purchase a power bleeder. Its worth it and I wish I would have when I did mine
Melting Slicks
Joined: Mar 2007
Posts: 2,520
Likes: 11
From: Hinckley OH
The brake fluid doesn't really care which caliper you bleed first or last. The only thing you MUST do is bleed the inner half of each rear caliper before you bleed the outer half. Bench bleeding the master cylinder has already been mentioned.
I'm not sure those bolts will stop fluid from leaking out the unused ports. Those ports will have a flared seat and it is the flare that seals it not the threads. Plugs should be available at any auto parts store.
I'm not sure those bolts will stop fluid from leaking out the unused ports. Those ports will have a flared seat and it is the flare that seals it not the threads. Plugs should be available at any auto parts store.
