Clutch master cylinder screw hole stripped/Looking for a master cylinder

[rstacy]

One of the screw holes used for securing the top cover on my clutch master cylinder is stripped. The screw is fine. Its the hole that is boogered.

I currently have a slightly longer screw in there which did bite but I am not happy with it.

 

Has anyone tried repairing the hole with a heli-coil

or

Does any one have a master cylinder that I can buy?

 

Thanks,

Ray

[Freebird]

I would think that you will be able to find a good used one pretty easily. If not though, you might be able to fill it with JB Weld and then drill and tap it.

[Flyinfool]

I would try a Heli-Coil before I tried JB weld.

The Heli-Coil will make it better than new.

This is of course assuming you have the tools to put the Heli-Coil in. You can probably by a replacement master for less that the coil kit.

[djh3]

Couple of ideas. I dont know so I'll have to ask a couple of questions. Is the screw hole open to the fluid or is it in a boss? How long is the boss? Is there room to tap it the same size and use the longer screw? Are the threads gone completly stripped or did it get cross threaded? If cross threaded you may be able to run a tap in and "straghten them out. Thats sort of a one time deal if they are not to messed up. You also could either put a heli-coil in it or just go to next size up tap. Down side of this is your going to end up with drill fillings in the resevoir. Maybe some tpae across it will elminate alot of that. The good thing about a helicoil is less chance you will cross thread it as the threads are usualy steel from there on. Cost becomes the driving factor unless you have access to the helicoils now. I think they will probably run you in the $20-30 range for a kit for the size you need. Next size up screww if you have the tap set nothing other than the time. You might have to clearence the hole in the cover a tad for the "new" screw.

[rstacy]

As I recall from having the cover off, the boss sticks up and for the most part is above the fluid level.

The threads are pretty much gone. Right now I have a longer 4mm screw in there but it is bottoming out and not letting me tighten the cover as much as I would like. Any shorter and the screw wont really bite.

 

I have a 4mm helicoil kit. I'm not sure if the boss has enough meat for the helicoil but I will probably give it a shot.

 

I will drain some fluid and make some kind of shield to catch the metal chips.

[GaryZ]

As I recall from having the cover off, the boss sticks up and for the most part is above the fluid level.

The threads are pretty much gone. Right now I have a longer 4mm screw in there but it is bottoming out and not letting me tighten the cover as much as I would like. Any shorter and the screw wont really bite.

 

I have a 4mm helicoil kit. I'm not sure if the boss has enough meat for the helicoil but I will probably give it a shot.

 

I will drain some fluid and make some kind of shield to catch the metal chips.

 

I recently had to put a heli-coil type of device in a Ford spark plug hole (aluminum head). The device came with excellent instructions specifying how to tap the hole without dropping shavings in the cylinder. Coat the tap with axle grease and the grease catches the shavings. In the case of your master-cylinder, I would consider leaving the top on and tight while drilling and tapping.

[Condor]

You might give this a try.

 

http://paint-and-supplies.hardwarestore.com/50-272-threadlocking-compounds/form-a-thread-thread-repair--613340.aspx

 

http://www.hardwarestore.com/media/product/613340_front200.jpg

[bkuhr]

. In the case of your master-cylinder, I would consider leaving the top on and tight while drilling and tapping.

hole and tap for helicoil would likely be larger than hole in cover, making you unable to leave cover on as suggested.

 

I usually stuff cylinders, etc with shop towels, blow out when done for larger clippings, then the fine stuff comes out with the towels.

[Flyinfool]

I would use either the grease on the tap and drill trick and/or tape over the small holes in the bottom of the reservoir till you are sure there are no chips left in there.

[rstacy]

The fix was just too easy.

When you remove the master cylinder cap you find that the boss is level with the top of the master cylinder. This is good because it is not submersed in fluid.

I took a piece of duct tape and covered the top of the MC. I cut a small opening in the tape to expose the stripped hole. This was to keep all of the crud and chips out of the fluid.

Then I drilled the hole and tapped it for the heli coil. Sorry for the bad picture but this is me tapping the hole. I wanted to keep the hole clean so I didn't use grease on the tap. I just blew the chips out using canned air.

 

http://www.raymondstacy.com/tap.jpg

 

I removed the tape after screwing in the heli coil and breaking off the tang.

 

http://www.raymondstacy.com/tap2.jpg

 

The reservoir was clean and crud free.

The new new threads worked great.

We are back in business and ready to ride.