Brake fluid reservoir / Master cylinder...

cloudsparrow

Just a quick question for someone... I'm sure it'll be a straight out yes or no!

I need to replace the brake fluid on my 1980 CB250RS. Problem is, the reservoir is petrified and the screw heads have been stripped. This is probably a silly question, but is it possible to just replace the reservoir, or do you reckon I'd need to replace the whole master cylinder, etc.? I'll probably end up taking it to the local Honda dealer; breaks are something I don't particularly want to mess up!

As you can tell, I'm learning as I go.
Wink

(p.s. - feels great to be back on the forum - it's been a while!)

Russell · Posted: Thu Jan 28, 2010 5:45 pm Post subject:

I'd suggest starting out by pricing a decent used complete master cylinder assembly from a wrecker as if it was cheap enough its a straight swap of part,refill with fluid, bleed, and you are done.

I had a quick look on a couple of parts sites and the various parts to replace the reservoir look to be available and not ridiculously priced but it may be that those problematic screws holding the cap down still need to be extracted to replace the reservoir.Perhaps you should take the whole front brake assembly off and carry it in to a small service outfit where you can talk directly to the mechanic.Who knows...it may be that those little screws can be extracted quite readily and quickly by an experienced hand with the right tools?

How butchered are the screw heads?If you have a small Philips driver it my be worth the gentlest of taps on top of the driver to seat it as firmly as possible then attempt to tighten the screw slightly.This might all best be done after having given a liberal dose of a penetrating fluid around each screw head and left it for a day to do its work. Often a stuffed up head will allow tightening as it is in the attempts to undo that damage is usually done. A slight tightening could break loosen the hold time has developed on the screw and allow it to then be backed out okay.

Good luck.

fasterspider · Posted: Thu Jan 28, 2010 5:58 pm Post subject:

Ebay has a master cylinder for you that will be brand new and only cost about $75.00

jvandyke · Posted: Thu Jan 28, 2010 6:56 pm Post subject:

I squirt each a bit of PB Blaster (stuff made to loosen things like this, there's others). Get right sized screwdriver and press down really hard while trying to loosen, a little tightening can't hurt (as said earlier). If that didn't work I'd cut a slot in what's left of the screw with my Dremel and use a straight slot screwdriver on it. If that failed, I'd grind the whole head off, pull the cover and then rip the screws out (but I don't know the design of your MC and can't find a good picture so that might not work). Only after I destroyed the already useless parts would I go buy replacements because well, I think it's fun to try.

confish86 · Posted: Thu Jan 28, 2010 10:20 pm Post subject:

Sooooo !! how did you make out on the master ???

I just ran into this on the Magna i have. Screw tops were all messed up , so i sprayed PB blaster on the tops & used a 10mm socket to cover over the screw head & tapped the socket with a small hammer . I did this several times to kind of help the PB stuff the seap under the head of the screw. Then i have one of those screw removal tools from sears & they backed right out. Razz

cloudsparrow · Posted: Fri Jan 29, 2010 3:44 am Post subject:

Thanks for all your ideas! I've been at work all day so haven't had a chance to check anything out yet.

So the plan is:
1. Trying out all your tricks with the stripped heads. If no success...
2. Track down master cylinder from wreckers / ebay.

Will let you all know how it goes.

(May not be ASAP as the fluid is still okay for now and don't want to put the bike out of service while the weather is so good!)

confish86 · Posted: Fri Jan 29, 2010 10:44 pm Post subject:

Don`t know if you have a Sears down under but here is what i`m talking about http://www.sears.com/shc/s/p_10153_12605_00952154000P

Works like a charm Wink

cloudsparrow · Posted: Sat Jan 30, 2010 1:51 am Post subject:

Cheers for the heads up. I'll give it a shot with the tools I've got and, if no luck, will try to find something similar to the damaged screw remover set you posted at our local hardware store.

jvandyke · Posted: Sat Jan 30, 2010 8:39 am Post subject:

I think "easy out" was a brand name for them too. If enough of the head is showing, cut a slot in it and use a flat head screwdriver, if you don't have a dremel, a hacksaw blade should do it, just takes longer.

CBX-tras · Posted: Sat Jan 30, 2010 5:21 pm Post subject:

FYI, a 50/50 mixture of acetone and automatic trans oil will work better than PB Blaster any day and cheaper too.

Proven to be a matter of fact by the fine engineers at General Motors.

fasterspider · Posted: Sat Jan 30, 2010 6:13 pm Post subject:

confish86 · Posted: Sat Jan 30, 2010 11:00 pm Post subject:

bikeboy

cloudsparrow · Posted: Mon Feb 08, 2010 3:29 am Post subject:

Sounds like a plan. The whole reservoir is looking pretty petrified and worn so I'm keeping an eye out for a replacement. No hurry, though, so it's all good.

And, Ian, I haven't touched the forks (realised I never needed to - it was just a dodgy mechanic) but have repainted the exhaust and everything else is running beautifully... which is fortunate, what with all the beautiful riding weather we've been having!
Twisted Evil

I'll keep you posted.