KE38 Master Cylinder help

[cayza]

Hi everyone,

First time post and newbie with all the mechanical stuff. My KE38 is leaking between the master cylinder and the brake booster (pictured). The master cylinder is the PBR square type and looks to be leaking between the flange to the booster. Just after some advice before I start pulling things apart, is there a after market master cylinder that will bolt straight on to the booster? I've had a look on ebay, but the flanges look a little different to what i've got. Or could it be something else that would cause the leak. I know it's hard to tell without actually looking at it but just after some advice if anyone has come across this before?

Sorry if my post seems a little naive, just starting to learn the mechanical side of cars. Gotta start somewhere.

Cheers, Caylan

[altezzaclub]

That's the rear seal leaking, just like you said.

Cylinder like this?  Dual aluminium PBR.

https://www.ebay.com.au/itm/Brake-Master-Cylinder-Toyota-Corona-RT118-2-0L-Wagon-1-1976-12-1977-Suits-PBR-b/222825521584?hash=item33e16fa1b0:g:dKoAAOSwON5bmpRS:sc:AU_ExpressDelivery!2000!AU!-1

Pretty damm expensive at $240.  As far as I know aluminium ones don't get rebuilt once they're old & ruined, unlike steel ones that you can hone out and re-seal.

You could strip it, clean it and try a $20 seal kit off Ebay, and if it still leaks then its a new cylinder.  Make sure the seals fit the PBR cylinder diameter & shape, and not just the Jap cylinder.

We had trouble getting out the floating piston in the rear brake half of it, but if you can get it apart and cleaned it may re-seal OK.  Get the diameter off it too, and see what else looks like that from a different car. Ford and Holden used similar master cyls, but probably larger diameter pistons.  Find an exploded diagram on the web, you have to take the plastic reservoir off and take out the mounting screw underneath as it hold the front pistons in.

You could convert it to a Jap master cyl setup, but that depends on bolt spacing and the reverse pressure limiter.  The jap system runs one master cyl and does the rear limiting in a little T-junct box on the firewall, so you'd need that too.

See how you go-

 

Edited September 24, 2018 by altezzaclub

[cayza]

Thanks heaps for the info @altezzaclub That one on ebay pretty much looks exactly the same. For now I'll keep that as a last resort, however I will contact them to make sure it'll actually fit if I need it.

Sounds like a plan, I'll strip it, give it a clean and try a seal kit and in the meantime I'll ring around a few wreckers and see if I can find a decent second hand one just to get me back on the road. I've got a workshop manual so I can use that for reference to help pull it apart. If that doesn't work I'll suss out either getting it rebuilt or converting it.

Again, I really appreciate you taking the time to help steer me in the right direction.

Note: This it what it looked like after I took it off...

 

[Big G]

I had the same unit from my daughters KE55 rebuilt with a stainless sleeve installed and new everything else for $195. It was a 6 hour turn around from when I dropped it off to when I picked it up. Just like a newy and the sleeve will never wear out or so they say.

[altezzaclub]

Those sleeves are a nice idea Graeme, its good to know they work as advertised.

The Corona pair we stripped last month were not corroded inside, but filled with tarry gooey mush. The main cylinder opens up with those two tabs you can see at the sides of the end cover disc. Give the business end a clout on a piece of wood while facing upwards and the first piston will come out. Then pull off the plastic reservoir & take out the bolt that holds it on, and that will allow the front piston to slide back out.

Then undo that giant hex nut beside the main cyl and there are floating pistons in there that limit the pressure to the rear wheels. They were jammed on ours, so we fitted new seals to the main cylinder only.  When we put it in the car no fluid went to the rear brakes at all, and only after a couple of weeks of driving did it free up and work. Those problems all stemmed from the cars sitting for years without being driven, so yours might be sweet.

I expect all the cars at the wreckers who used those cyls will be just as bad inside, unless you're lucky enough to find one that has already been renewed.

The booster just needs a wire brush, some brake-clean and a spray of paint.

[cayza]

@Big G That'll most likely be my next option if this seal kit doesn't work. Not sure who you used but I seen on a couple of threads people using a company up in Qld called "Master Cylinder Exchange". Being down in Vic I'm sure I could find someone locally.

@altezzaclub I started to pull apart the master cylinder and had the same problem, unscrewed that hex nut and the seal block did not budge. Tried to give it a knock as per the service manual, I might have been a bit to careful, but wouldn't move. Seal kit arrived this afternoon so I'll give it another go over the weekend. If it doesn't budge I'll follow on with the rest of the instructions and see how I go.

Again, thanks heaps for the information, it's been fun getting stuck into it.

Edited September 26, 2018 by cayza

[Big G]

The best way to learn how something works is to pull it apart. But always take note of the order and direction of components sometimes its critical.Even use witness marks I find them helpful. I got my resleaving done on the Southside  of Brisbane so no help to you. Go the Google and make some calls it is a pretty standard price that they can quote you over the phone. Good luck.

Edited September 26, 2018 by Big G
Typo

[peterd]

The reason the eBay one is so expensive is that they don't make this one any more. (pbr) Buy a rebuild kit and have a go. Mine was leaking the same as yours. My skill level is very basic and I managed to make it work it again. I have one for sale on gumtree if you're desperate, but I think you'll be fine with the one you have. 

Edited September 29, 2018 by peterd