Brake Master Cylinder Upgrade

Re: Brake Master Cylinder Upgrade (TwoDogs)

Tue, 20 Feb 2018 14:01:01 GMT

Ok finally on the road again and can report the brake pedal is higher as expected and desired from the slightly larger master cylinder. Stock 1991 calipers / rotors are not the most powerful in the world, but they work fine.

Re: Brake Master Cylinder Upgrade (TwoDogs)

Fri, 19 Jan 2018 10:56:36 GMT

Ok, I fitted a 15/16" master. The plastic reservoir from the 7/8" needed minor work to fit the new one. Namely the plastic that surrounds the bolt hole fouled on a bit of the master cylinder. I had to carefully remove about .5mm from a segment of the plastic circle, with a soldering iron. Then happy days. Bench bled, fitted, bled at calipers and bingo.
The pedal is hard and at the top. Car is not yet drivable, due to other changes(Led lights, new boost gauge in dash and soundproofing the cabin) but already I can see the brakes will be nice. Retained the orig fat booster and the ABS (jury still out) and stock rotors and calipers. Will give final thumbs up/down after driving.....
Thanks to all for the helpful advice......

Re: Brake Master Cylinder Upgrade (GDII)

Fri, 22 Dec 2017 12:30:19 GMT

I installed a 1" master from a Previa van into my 1990. All I needed to do was swap over the reservoir to get it to work. I also have a 15/16th master from a Previa that I might use as the pedal for street driving is quite heavy. Fine for the track once you get heat in the brakes (semi track compound pads) but not going to do that for some time now. Both are aluminum and a direct swap for the cast steel 5/8ths. They are all non abs units.

What I do need is the 1992+ booster. I've installed a 1994 proportioning valve already so it's the last thing I need to do to swap from GEN1 to GEN3-5 brakes.

Re: Brake Master Cylinder Upgrade (Reddtarga)

Thu, 21 Dec 2017 11:10:49 GMT

With the original aluminum Aisin 4 bolt M/C's that were fitted to MR2's, Supras and Land Cruisers I have found the seals and hole spacing is the same and have swapped some of them over OK.
I found the holding screw can be very tight and a good screwdriver is needed.

By 'generally interchangeable' I meant different reservoirs can be swapped OK but the connectors will be different. The connecting pipes may also foul the reservoir.

Re: Brake Master Cylinder Upgrade (TwoDogs)

Thu, 21 Dec 2017 09:38:58 GMT

Thanks Redd, not sure what the "level connector" is. Just wondering about the 2 supply/return holes with seals on the top of the M/C. They would need to be the same distance apart and not have different flanges/lips.
But seeing as you say they are "generally interchangeable" I'll go ahead and purchase the m/c. Hope it comes with new seals. If the reservoir doesn't fit, I'll send the Carlton Crew round to talk to you..

cheers,

Re: Brake Master Cylinder Upgrade (Reddtarga)

Thu, 21 Dec 2017 08:18:57 GMT

"The reservoirs are different shapes, but maybe they fit onto each other's master cylinder ? Does anyone know if the original 1990 reservoir fits onto the 1993 master cyl ? "
Reservoirs are generally interchangeable but you don't need to change it. The level connector on the replacement M/C can be left unconnected if the plugs don't match.

Re: Brake Master Cylinder Upgrade (5SGTE)

Wed, 20 Dec 2017 23:33:09 GMT

You tried anyone local, supercheap, repco, bursons, napa?

Where are you? If your local my usable original in chillin just over there on the shelf... Happy for you to borrow it to buy some time.

Re: Brake Master Cylinder Upgrade (TwoDogs)

Wed, 20 Dec 2017 23:15:33 GMT

I sms'd Josh a couple of days ago and have not had a response. My window for working on the car means I need to buy immed.

Re: Brake Master Cylinder Upgrade (Danti)

Wed, 20 Dec 2017 22:27:57 GMT

Also make sure LHD fits RHD.
Have called the mr2 wrecker from melb.

Re: Brake Master Cylinder Upgrade (TwoDogs)

Wed, 20 Dec 2017 19:47:13 GMT

Ok, turns out that Redd's post on page 1 is what I need. The 15/16 (130.44906) is a direct replacement for the earlier 7/8" (130.44903). They are available from the US, but commonly, without the reservoir !! The reservoirs are different shapes, but maybe they fit onto each other's master cylinder ? Does anyone know if the original 1990 reservoir fits onto the 1993 master cyl ? (hoping to save a few $$).

Thanks Danti, you were saying the same master cyl.

Re: Brake Master Cylinder Upgrade (Reddtarga)

Tue, 19 Dec 2017 16:06:43 GMT

The later 15/16" M/C with thin booster should fit OK, but because of the width of your fat booster, the M/C pipes obviously won't. (may not matter if you get ABS bypass pipes made)
You'll need to get under the carpet to replace the booster, but not to replace just the master cyl.
BTW, if you were to replace only the M/C, the push rod clearance between it and the booster should be checked in accordance with the service manual.

Re: Brake Master Cylinder Upgrade (Danti)

Tue, 19 Dec 2017 14:51:55 GMT

My understanding is you can get the later model M/C and booster and fit direct to your 90 model.
Few guys have mentioned that here.
Like what's been said make sure
You match abs with abs if you have abs.
Also the later model booster the vacuum valve is at the back. I remember reading is some where.
I have a 90 model fitted with 15/16 later model mr2.
Guys can correct me if I'm wrong

Re: Brake Master Cylinder Upgrade (TwoDogs)

Tue, 19 Dec 2017 14:43:39 GMT

Amayama notified me that they cannot supply the m/c rebuild kit for the early m/c.
So back to square 2...
Does anyone know for sure of a bolt on M/c (+/- booster) which will replace my 1990 ABS m/c with fat booster ?
One more question, do I need to get under the carpet to replace the master cylinder (and poss the booster)?
Because over Christmas/new year, I will be putting some sound proofing in. Was hoping to reco the m/c in that time
but now I think the brake upgrade won't be in time. (I don't know what to get yet :o)
thanks for your help.

Re: Brake Master Cylinder Upgrade (TwoDogs)

Fri, 15 Dec 2017 14:51:45 GMT

Thanks Redd, checked Amayama and they appear to have it, so have placed the order. Cheaper than the US also.
Yes it would be a good idea to take the m/c out, but that takes the car off the road until completed.

Re: Brake Master Cylinder Upgrade (Reddtarga)

Fri, 15 Dec 2017 10:07:40 GMT

TwoDogs
This morning, the only place in the US that did not list the reco kit as Discontinued, sent me an email
to say they can't fulfill the order. So looks like I will be fitting an m/c from a different car.

Have you tried Amayama or Lithia Toyota parts?
You'll need the correct part Toyota number for a reco kit for your year/model.

Also could be a good idea to pull the M/C and check the bores before spending money on a reco kit.