mk2 brake master cylinder upgrade

[SuperRedMR2]

Does it matter if I buy a master cylinder that is off of the ABS model?

[tommundy]

You want a non-ABS one afaik.

You'll also need to bend the brake pipes to fit the new cylinder.

[Steve Horrocks]

It's a non ABS one & rev2 onwards as well (15/16's) early mk2 was 7/8's same as a mk1.

[SuperRedMR2]

You want a non-ABS one afaik.

You'll also need to bend the brake pipes to fit the new cylinder.

Thanks Tommy, was unaware of that...Don't really want to be bending pipes in case they snap...May not get this after all.

[Steve Horrocks]

The bending is really just a case of gently manipulating it by hand to be a touch lower. No big deal really.

[Neil_turbo]

was barely any bending needed for mine, really no big deal

[aw11rally]

was barely any bending needed for mine, really no big deal

Is it worth doing Neil? Noticeable difference? Theoretically you need to press harder but less travel in the pedal, is that what happens in practice though?

[Neil_turbo]

I did this as i have changed my calipers to a rev3 turbo set up, so the standard mk1 MC just didnt shift enough fluid (these have twin piston fronts)

I never really had any issues on standard brakes, so for me i wouldnt change it, if running standard calipers. I guess if just doing this it will decrease feel

I am effectively now running a standard late spec mk2 set up, as even my discs are off a mk2 now!

At the weekend we gutted the bias valve, so will see what happens at the first sprint a week on sunday!

[aw11rally]

I see, so you shouldn't notice any difference as I guess the ratio of MC to piston size is unchanged i.e. As Toyota intended.

We're running huge bremsport 4pots (over 300mm disc) up front and mk1a fronts on the back. The MC is the standard mk1a jobbie, we've got a very long pedal but it requires very little pressure. Occasionally it goes straight to the floor which can be unnerving at high speed. At present I'm not sure whether this is pad knock off after high G corners, the lack of fluid volume moved by the standard MC or the poor vacuum from the ITBs.

I think a mk2 15/16 MC will be the first thing to try.

We currently just drive around the problem with a little left foot braking on the straights at full throttle, this seems to solve the problem. Can cause stained boxers when it catches you out though.

[Lauren]

Doh thought the post was about the servo rather than the master cylinder(!).

[PW@Woodsport]

I would say putting a MK2 master cylinder on is a downgrade

Well you're wrong, it moves more fluid at a slightly lesser pressure, reducing the Mk1's tendancy to lock the fronts, resulting in better stopping power and a reduced overall stopping distance over stock.

Coupled with the twinpot Celica calipers and a gutted bias valve it's one of the best brake upgrades you can do to a Mk1.

The above is proven fact over ten years of doing this.

[Lauren]

As I said in my previous post I misunderstood and thought the topic was about the servo, not the master cylinder.

[IanParkhouse]

Oh no! I'm slowly losing brake fluid!

I've ordered this:
https://www.ebay.co.uk/itm/Toyota-MR2-M ... 0227.m3827

Which I think is the appropriate Mk2 version.

Was thinking I'll throw a seal kit in when it comes, does this look like the right kit: https://www.sparepartstore24.co.uk/7799197-abs

[BertranTibo]

free