Sorry.....not talking about bleeding the master cylinder..... I want to remove the plastic reservoir from my master cylinder and replace it.
I'm asking for some tips to get it off..... as I'm fairly sure it's really on tight since it has a wedged-in "O" ring sealing it to the master cylinder.
Mike, all that is required is to have forearms like Popeye.
Just kidding, a bit of muscle required.
After removing ALL of the brake fluid the resevoir can be rotated 90 degrees allowing you get a grip to either push or pull the plastic cup out of the metal base.
Mike Cecchini wrote:Sorry.....not talking about bleeding the master cylinder..... I want to remove the plastic reservoir from my master cylinder and replace it.
The 'bleed it' comment wasn't aimed at you Mike - It was an answer to the original posters question . . . . which has otherwise been ignored here
Sorry Don...... didn't mean to hi-jack the thread...... just needed to know what he did to get the *&^%$ plastic reservoir off.
I find it hard to believe he dosen't know to bleed the system once it's been opened.
Bench bleeding isn't necessary......and while it helps a little...... getting the master cylinder on the bike with all the brake fluid drooing about while you frantically get the banjo bolt into place with new COPPER crush washers.... is such a mess..... I hardly think it's worth it.
Just another reason I love DOT5 brake bluid...... no problem at all getting it all over everything with ZERO problems.
Mike Cecchini wrote:Bench bleeding isn't necessary......and while it helps a little...... getting the master cylinder on the bike with all the brake fluid drooing about while you frantically get the banjo bolt into place with new COPPER crush washers.... is such a mess..... I hardly think it's worth it
Bench bleeding probably is necessary if you can't get any 'pedal' at all . . . . and of course it doesn't have to be done on a bench . . . . it can be done with the cylinder on the handlebars
If you remove the hose between the M/C and the splitter at the splitter and stick that end in the full reservoir, a dozen pumps or so should get it bled and get the fluid flowing. Then you can reattach the hose end to the splitter and bleed the system as normal
The plasic reservoir (as we all know) is sealed by a rubber O-ring. Problem in removal is due to the alloy "case" becoming corroded restricting the O-ring. As said before, twisting the reservoir to a point where you can get good purchase often solves the immediate dilemma. However, this may result in a distorted reservoir complete with damaged O-ring. Upon assembly with new components, I apply Dow Corning silicone grease to the O-ring, inner alloy "case" & retaining screws. This ensures easier removal "the next time"... Oh..DOT 5 ( NOT 5.1) here too, but be aware it cannot be contaminated with any other fluid or rubber components & tends to be a little "spongy".... Take time to read up on it before making the decision to install. Lots of good stuff ( & opinions) on Google..
Agreed on your plastic reserviour comments and thoughts Limey. If I was going to reuse the existing "O"-ring and plastic reservoir I'd be a bit worried since the originals are in horrific condition. I'm fairly sure both will be damaged on seperation, but since I have new spares, I'm not too concerned.
I am, however, hoping the master cylinder "O" ring sealing groove is in useable condition so I don't have to replace the master cylinder.......and god only knows where I'd find one of these.....at any price.
I couldn't agree with you more on the use of silicone grease upon reassembly and I've been using DOT 5 fluid on/off the track in BMW's, Ducati's and my X's since Dow Corning brought it on the market back in early 80's........so no worries there.
Feedback: After getting the resevoir to a point where I could rotate it, I finally had to use 2 flathead screwdrivers to pry it off, my arms just could not get it done alone! It looks like the resevoir survived intack. I purchased a new o-ring as the old one was in bad shape.
Question 1: If I use silicone grease on the o-ring as suggested here doesnt that introduce the possibility of the grease getting to the bottom of the resevoir and plugging the tiny holes at the bottom?
Question 2: I have not taken out / apart the piston. If I fill the metal resevoir (I have not put the o-ring and plastic resevoir on yet) and actuate the piston should I get fluid coming out the bottom port (remember I have the unit on the bench, not the bike)? I dont want to put the o-ring and unit back together only to find out I should have taken out / cleaned / replaced the piston.
Thanks for any help!
PS During the process I found out my '82 has a 79 / 80 M/C - dont know if one was better than the other or if the previous owners had swapped one for the other during a rehab??
Q # 1: If I use silicone grease on the o-ring as suggested here doesnt that introduce the possibility of the grease getting to the bottom of the resevoir and plugging the tiny holes at the bottom?
A #1 Only use a smear of silicone grease on the "o" ring and inside of the hole where the ring slides in. No problems.
Q # 2 I have not taken out / apart the piston. If I fill the metal resevoir (I have not put the o-ring and plastic resevoir on yet) and actuate the piston should I get fluid coming out the bottom port (remember I have the unit on the bench, not the bike)? I dont want to put the o-ring and unit back together only to find out I should have taken out / cleaned / replaced the piston.
A. #2 That's the risk you take when you short-cut a full disassemble and inspection..... but if things look and feel good with the master cylinder.......then it seems reasonable to put it back on the bike and assemble all parts and bleed it for use.
The amount of brake fluid that is used when pulling in the brake lever is very small.I have bled the master at the top-bench bleed-with the hose in place. Sometimes opening the banjo bolt at the master first and then pulling in on lever,then closing bolt,then releasing lever until you can start to feel resistance in the brake lever.Then go down to the beeders at the calipers to finish the job.I've also tapped on the master resevoir with the top off and got air bubbles to come out of the master witch also speeds things along.Sometimes this process is lenghty and frustrating.Also as Mike has said if the master is full of crud it's not going to work as well.
Mike