'79 R65 Front Brake Locked, Can't Open Tank & Unknown part

[at1rest]

Seth ...
Thanks for the hint on the gas cap you were right I had it backwards. Gas cap is off now no problems.

As to the stuck brakes I open the Reservoir up on the handle bar and had a look and the fluid. It was really old looking so I closed it back up.

I got down by the caliper and thought maybe first I ought to just try to open the bleeder Port down there but I could not budge the nut.

I sprayed it with some WD-40 right around the edges making sure not to get any on the tire or the disk and also got a little bit around the nuts that are holding the caliper on to the fork and will have a go at them tomorrow.

Thank you everyone for the advice.

[at1rest]

Yes, the master could very well be stuck.
If you loosen the bleeder on the caliper to release the pressure, you can try rotating the tire. And yes, the master cylinder is on the handlebar with the reservoir. You need to remove the bolt the handle pivots on. The handle presses in on the piston. There is an inside circlip keeping the piston in its bore.

thank you.
that's very clear.
much appreciated.

[Kurt in S.A.]

Note...WD-40 is not a penetrant, it is a water dispersant liquid and eventually attracts dirt. Get some PB Blaster, AeroKroil, or mix a 50-50 blend of ATF and acetone.

Kurt in S.A.

[at1rest]

Note...WD-40 is not a penetrant, it is a water dispersant liquid and eventually attracts dirt. Get some PB Blaster, AeroKroil, or mix a 50-50 blend of ATF and acetone.

Kurt in S.A.

Thanks Kurt!
Found PB Blaster at my local Home Depot.

[Rob Frankham]

Yes, the master could very well be stuck.
If you loosen the bleeder on the caliper to release the pressure, you can try rotating the tire. And yes, the master cylinder is on the handlebar with the reservoir. You need to remove the bolt the handle pivots on. The handle presses in on the piston. There is an inside circlip keeping the piston in its bore.

If you remove the two allen screws that hold the master cylinder onto the handlebar mount, the whole thing will come away... you don't have to remove the lever. This allows you to work on the assembly away from the bike (always a good idea with brake fluid involved, don't forget Brake fluid is a pretty effectve paint stripper) and makes access to the circlip much easier to get at.

As a matter of interest, that part is for a 16mm master cylinder which would normally be fitted to a twin disk machine. It's not certain bacause the larger master was sometimes retro-fitted to single disk machines replacing the 13mm master that would normally be fitted. My point is that, if the bike only has one disk, this may not be the right piston...

Rob

[at1rest]

mistake

[at1rest]

Rob,
Good info and a good point about possibly "not the right part" and this reminds me of an other thing yesterday. (Battery below)
This also makes me wonder about brake fluid and what was originally used in there.
I've read that you need to change all rubber if going from Dot 4 to Dot 5 and if I really don't know what's in there now
then should I just change all rubber parts anyway and use Dot 5?

Yesterday, I rediscovered what I thought was a new battery for the R80.
When I fist went over there months ago, it was sitting on the back rack of the R65 with 2 battery chargers so when cleaning up I just put that stuff in a cabinet in the back.
So yesterday I put my multi-meter on it and saw 11.8x volts or so. Measured it, and compared it to the size of the almost dead, 2.xx volt one in the R80 and it is the correct size, but the Plus / Minus terminals orientation is reversed.
Also compared it to the battery in the Husky Lawn Tractor but again correct size but orientation reversed.
No other vehicles on the property that use a battery other than the R65 which is a smaller size.

So, neither of the chargers are "intelligent" and only one has a progress / percentage of charge meter on it.
I know to charge a 2 amps and there's a 2/6 amp switch on the better one, but do I have to sit there and watch it the whole time or just check back every hour or so and then if I have to leave for a long time is it ok to disconnect and continue later?

Thank you!

[at1rest]

redundant

[at1rest]

redundant post

[Seth]

Most likely, there is DOT3 or 4. Usually DOT4. So unless someone previously converted to DOT5 (unlikely and probably not recommended), use DOT4.