KYcrawler

I recently put a new master cylinder on my '87 runner because I have been having a problem with the pedal doing next to nothing on the first press and it works just fine on the following press of the pedal. Not everytime but about one out of four times this was happening. The problem is I don't know if the condition is still there because before I got a chance to bleed the brakes I noticed a leak on the reservoir made a puddle in my garage the next afternoon. Here is my question, is there an o ring I missed when I reused the old reservoir on the new master? Or did I not crank down on the gromet holding the reservoir down enough? If anyone has an exploded view or a pic it would be nice. Thanks in advance.

yayfortrees

There is probably an o-ring there, or there is supposed to be one there.

Did the new MC come with a new reservoir? Assuming the reservoir is almost empty by now, you might as well take it off and inspect it.

Once that is all taken care of, do you already know the procedure for bleeding the brake system?

Pool Playen Bob

exploded view or not you'll have to pull it apart and see what exactly is was leaking. i just did mine last winter and i cant remember if i got a new tank with it or not. pull out the old o-ring and slap in the new one. and if its still soft you may still have air in the lines.

KYcrawler

The new master cylinder did not come with a new reservoir. I am sure I will have to pull it back off, I was just wondering if I had to find a new gasket/o-ring or something.

PismoJoe

Yes, there is an o-ring right below the bolt that holds the reservoir tank on.

I don't think I've heard of a MC that didn't come with a new reservoir, thats really lame!

Pool Playen Bob

ubber lame. my probe back in the day didn't come with one. you'll just have to pull the o-ring off and take it to your parts store and have them match you up a new one. less then a buck im sure.

KYcrawler

I agree, the mc not coming with a res. is very lame. I should take the blame though because I folded on my vow to never buy anything else from autozone. I built a Bronco a couple of years ago and used they're junk to do it. I swore them off forever but they are close to the house, cheap, and I was being lazy. Anyway I guess I'll go to napa and buy a new one and throw out the reman.

PismoJoe

This is a hard deal to beat, OEM Aisin...will last you another 20 years lol

http://cgi.ebay.com/ebaymotors/Toyot...item439ecd9e17

betelnut

The Toyota EPC shows two 'grommets' that fit into the master cylinder's front and rear system inlets. The reservoir fits directly onto that. I doubt that the reservoir would even appear to fit without those grommets.

Part numbers for the grommets are 47255-16010.

KYcrawler

Thanks for the exploded view. Where did you find it? That looks like the master cylinder I have but my reservoir is slightly different. By that diagram it doesn't appear to have an o-ring between the the res. and the master or the grommet and the res. That's what I was wondering. I guess maybe I accidently cracked the res. Or didn't crank it down enough to get a good seal. Thanks guys.

PismoJoe

I think that this is the one that should look exactly like yours

yayfortrees

Hey, that looks like a page out of a FSM! Why would you look there?!

yayfortrees

Good idea. The way it's typed out is technically not correct, but the theory is very sound and true.

I'm not trying to bag on you gnarly, because you raise a very valid point. I will explain it the way I understand it, just to avoid confusing any newbs that later read this. I'm not trying to offend you in any way.

If the bearings are loose (worn-out or not enough pre-load), they will allow the entire hub to wobble. Since the rotor is attached to the hub, the rotor wobbles as well, pushing the pads and pistons away from the rotor. Then, when you press the brake pedal the first time, the pistons and pads have too far to travel to contact the rotor, requiring you to pump the brakes.

I know you know what you meant gnarly, I just don't want newbs getting confused about the terminology. Again, no offense intended. Just a technicality.

betelnut

Oops, sorry, PismoJoe is right. The pic I posted was from a '95.

betelnut

Ok, here's the EPC diagram for the '87, I believe.

Maybe you're looking for the 'ring', 47202T? Toyota p/n 90301-14001. Should be a few $$$ each at the dealership.

thralldad

I haven't found any aftermarket brake or clutch MCs that last more than a couple of years.Grrrr.

KYcrawler

I fixed the leak for sure, and I am pretty sure the pedal problem was solved with it. I popped the hood when I got home from work and noticed the fluid was still just below minimum and could clearly see the leak is where the reservoir sits on the master. I grabbed the old master to see if maybe I missed an o-ring during disassembly and realized there was a rubber gasket for the bottom of the reservoir that had totally crusted over to the point that it looked like part of the cast metal on the res. I cleaned it up and checked it for rot. Installed it, bled everything and drove around the block several times. Seems good, but Since I built the driveshafts it became strictly an offroad toy so I won't feel great about it until I can trailer it somewhere to put it through its paces. Thanks again everyone for your help.

betelnut

So, was it the o-ring that PismoJoe and Pool Playen Bob thought it was?

KYcrawler

It was in the diagram that Betelnut posted. Just below the M.C. in the picture.

KYcrawler

My bad I just realized you posted it