I just swapped over a TSM rear disk kit to my 73 FJ40. Most guys put a Prop valve on the rear, but I want to upgrade my MC also.

So I am thinking about going to a 93ish FJ80 MC so I won't need the proportioning valve. I know a few guys have done this already. (yeah I searched, but didn't get much detail :flipoff2:)

My questions are:
Are the brake line fittings a direct bolt in to the MC?

How much has to be removed from the rod/plunger that goes into the MC?

Thanks,
Phil

Good Post!

I am looking for info on this as well for my 60!

Thanks

as am I on my 45LV

The fittings are all the same, but the ABS model has the rear circuit in the front and the lines enter from the top and the front circuit enters from the side at an angle. The non-ABS model would probably be a better choice as both ports are on the side and are at 90 degrees to the MC.

I have an ABS model installed in one of my cruisers and there is minimal push rod adjustment, just adjust like the FSM tells you.

Of course depending on the weight distribution, a proportioning valve may still be needed. An 80 probably has a different distribution than a 40.

Dave

Non-ABS model will be for rear drum brakes. There might be a check valve in the rear circuit.

The fittings are all the same, but the ABS model has the rear circuit in the front and the lines enter from the top and the front circuit enters from the side at an angle. The non-ABS model would probably be a better choice as both ports are on the side and are at 90 degrees to the MC.

I have an ABS model installed in one of my cruisers and there is minimal push rod adjustment, just adjust like the FSM tells you.

Of course depending on the weight distribution, a proportioning valve may still be needed. An 80 probably has a different distribution than a 40.

Dave

Thanks, this is what I was looking for :)

I specifically want the RR disk model, so I guess that means ABS? I was under the impression in 1993, rr disk was non abs.

Without an FJ80 FSM, I would have never thought the circuits to be reversed on the MC.

Phil

All rear disc 80 series (at least in USA) are ABS with FF rear end. I don't know what difference ABS makes in the master cylinder, other than possible check valve in rear circuit. Maybe the lines exit the master differently to interface with the ABS module.

Specter (http://www.sor.com/sor/products2.tam?xax=21567&category%2Ectx=014%2D01&page%23%2Ectx=014) shows several listings for 80 series master cylinders, with an w/o ABS. I recommend asking them what the difference is between ABS and non-ABS 80 series master. If you ask, please follow up here.

Doh! I didn't think about Specter's site. Thanks for the link.

I have an excellent parts person at my local dealer. I'll have her look up some info. I haven't had much luck talking with Specter's sales drones.

FWIW, both AllPro and Marlin list a non-abs FJ80 MC as an upgrade. AllPro indicates thiers is meant for rear disks.

If this gets too confusing, I'll just get a Prop Valve :rolleyes:

Phil

yes a SOR non abs 80 master/booster works great for rear disc, have one on my fj55-100..................

yes a SOR non abs 80 master/booster works great for rear disc, have one on my fj55-100..................

Do you have to run a proportioning valve with it?

Thanks,
Phil

Following up after looking in my '93 factory manual. It shows ABS and non-ABS versions of the master cylinder.

Externally, there is a different in the brake line port locations; however, the #1 and #2 pistons are in the same locations, and the #1 and #2 ports look to be in the same order.

Internally, the piston springs and cups are different but not much. There doesn't appear to be a residual valve in the rear circuit, but I haven't taken an 80 series rear drum master apart to verify.

I suspect either ABS or non-ABS master would work fine. Anyone want to buy one of each and give them a try :)?

Anyone with a FJ80 (or rear drum FZJ80) rebuilt his master cylinder? Was there a residual valve?

Edit: adding pix.

80 series masters, external (http://home.earthlink.net/~cruiserman/80seriesmaster1.jpg)

80 series masters, internal (http://home.earthlink.net/~cruiserman/80seriesmaster_internal.jpg)

After more research here's what I know and what I did:

I finally decided on using a 93 FZJ80 non-abs MC.

ABS or non-ABS does not really matter as far as function of the MC is concerned. There are differences in where the brake lines connect, but that's about it. 4 wheel disk also does not matter as far as the MC is concerned. There's no difference for for 4 wheel disk.

As Beanz2 said above, the addition of a proportioning valve may or may not be necessary depending on the weight distribution of the vehicle. All vehicles with front disk and rear drums have a proportioning valve of some kind from the factory. I suspect that vehicles with drums on all four wheels probably do not have a proportioning valve from the factory. Maybe someone can confirm or refute this?

For my installation on a 73 FJ40:
Specs: Minitruck front disk conversion with larger calipers and vented rotors, TSM RR disk kit, Mico line lock on the rear circuit and, I believe, the original drum brake booster.

The MC bolted up with only a small amount removed from the rod/plunger. I trimmed it 1/4", but it only needed about an 1/8".

After completely purging and bleeding the system, the brakes function ok. However, the pedal is hard and does not go all the way to the end of it's travel. I absolutely cannot lock up the brakes at all. It's almost as if the booster is not working at all, but I am reasonably sure there is nothing wrong with it.

The line lock was not engaged and there are no symptoms typically present when the booster is bad.

Any ideas where to look next?

Thanks,
Phil

Couple ideas that might help..
Flex hoses dropping to the axles.. Maybe too much volume and not enough pressure in the system? I've got the same situation on my FJ62 that you have right now.. I need to replace the drop hoses anyway just havne't gotten to it. have seen them rot inside thus causing problems.