Front Master Cylinder rebuild tutorial??

[Guest]

Is there a good Front Master Cylinder rebuild tutorial fro 77-79 GS750 anywhere on the site??

I have a new piston and cup set for it but i'm a novice and would like to see some pictures.

i did use the search feature but couldn't find what i was looking for.

thank you,

Gregory

[Octain]

Is there a good Front Master Cylinder rebuild tutorial fro 77-79 GS750 anywhere on the site??

I have a new piston and cup set for it but i'm a novice and would like to see some pictures.

i did use the search feature but couldn't find what i was looking for.
thank you,

Gregory

NOt sure but I dont think there is.
What did you need to know?

[gmoore]

i was just curious if there was some sort of step by step.

i haven't taken off banjo bolts before and haven't ever taken apart a master cylinder so i guess i'm a little intimidated.

[Hummer]

Although I'm on a 1000GL, I found the service manual helpful just as far as knowing where all the small parts were. I had so much rust built up that I couldn't distinguish between the retaining ring for the dust boot, the circlip, a plastic washer, or anything else! I used a small screwdriver to scrape away rust, parts cleaner to irrigate and compressed air to blast away the crap.

[Octain]

Understandable.. There may well be a thread someplace with pics. The first one I did another forum member helped me.
There really isn't much to em. The hardest part is removing the circlip.
You have a digital cam?

Just take it apart, clean and replace parts and put it back together. Be sure to have plenty of rags, brake fluid it brutal on painted parts.
I like to soak the main body after disassembly in Berrymans carb dip before I put em back together. There is a teeny tiny hole in the master cylinder itself that must be cleaned. Best bet is to use a thin copper wire from a wire brush.
After I soak a good coat of caliper paint makes em look new.

[gmoore]

thanks guys, i'll let you know how it goes.

I do have a camera and if i get stuck i'll be sure to post some pics so i can try and get some help.

[allojohn]

If you're buying a rebuild kit be careful. I bought the L&M kit for the front MC and it didn't fit. On the '78 the internals for the front and rear MCs are the same. I guess the same is true of '77 and '79.

On the tear down the only thing I found tricky was removing the snap-ring. You need snap-ring pliers with a reach of at least 1.25" and you have to compress the piston while reaching in there to get at the snap-ring. If you have three hands it will be easier.

Good Luck!

[DPage]

There is a perfect tool for getting the snap ring out, long-reach pliers from Mikesxs, part #35-0009, $11, called Right angle snap ring pliers. Also, I hope you got an OEM rebuild kit, much better than aftermarket stuff.

[Octain]

I've used OEM and aftermarket(K&L) without any issues at all. I would have used aftermarket for the one I used OEM but I couldnt find one anywhere in the world.

[gmoore]

i didn't get a whole rebuild kit. i got an OEM piston and cup set. i'm pretty sure that is what i need.

i have the whole brake system off the bike since i'm pretty much doing a frame up rebuild. is there an easy way to bleed the brakes? they have no pressure in them so i don't think the typical method of loosening squeezing and tightening will work. can i just dump it out?

i'm also replacing the lines if that maters. should i just pull it all apart and dump the fluid out?

i'm not entirely sure what is wrong with them and why there is no pressure. i just figured that it needed a new piston and cup set since the upper lines were cracked and there was fluid all around the master cylinder banjo bolt and no pressure and no front brakes.

[mike_of_bbg]

Beyond the piston and cup set, about the only other parts are the reservoir and o-ring (if applicable to your model).

Getting the master started is a frequent source of frustration. Make sure your MC's tiny little return port is free. Using a vacuum pump at the caliper is usually the best way to get it started.

[Hummer]

I was in the same boat a month ago, thinking that I'd just be replacing the lines. I disconnected everything, let gravity take care of draining most of the fluid and then just tossed the lines in the corner. When the parts come in to rebuild my MC, I'm going to try feeding the fluid from the bleeder screw up into the MC. I've heard that it works and I'm just curious to see if it really is that easy. Should take care of the problem mike mentions, I think.

[gmoore]

ahhh, instead of filling it from the MC.

let me know how that works.

i think i'll do the same and dump what i can out of the MC and disconnect everything and let gravity go to work.

is there anything that i should not get brake cleaner on?

i apologize if that is a stupid question but i'm really learning as go here.

[Hummer]

I picked up a syringe from the local pharmacy to remove the brake fluid from the reservoir - it worked great.

As far as the brake cleaner goes, I avoid anything rubber and clean up overspray off any painted or plastic surfaces as quickly as possible. I've never really had any problems on paint, but I don't want to find out I'm wrong either.

[allojohn]

Maybe all the brake fluid has already left the building. Tear it down.