Master cylinder cover bolts

[fieldy]

I tried using impact driver to remove them from the front metal reservoir and the plastic rear reservoir. How is the best way to get them out? I've never seen any stuck like this before. I got one bolt out on two trikes. They are Phillips. All of them were already stripped, wollered out.Will a certain brand of extractor do anything or are they toast?

[AK47KID]

Im not an expert ( one of the more knowledgeable guy will come around) but have you tried using a hammer and tap the reservoir to break the bolt threads loose? I did this to a banshee and the threads came loose

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[onformula1]

The problem is they are JIS screws, Japanese Industrial Standard. They are not the same as a Phillips bit.

[fieldy]

Anyone heat the cast type metal resivoir. Maybe drain the brake fluid and use a little heat? I know there is a rubber diaphram or two I would have to replace/rebuild.
Yes, it always seemed like Phillips were not quite the right fit. I have always been able to get them with the impact on other trikes but some genious worked on them before and i will never have a good bite. I have beat on some of the screws with a chisel trying to knock em loose. Blaster sprayed on them for a long time.
I will Google the JIT to try to find a bit. The fluid must have rusted them in, maybe to never let loose.
Im scratching my noggin on this. I dont want to buy new front master assemblies. I have seen
the little chisneeze metal colored resivoirs for the rear.

[RoscoW]

I've had a couple that were stripped as well and wouldn't come out so I chose to drill the heads off. It turns out that it wasn't the screw threads that were seized, it was the taper of the countersunk head stuck to the cover. once it was drilled the cover came off and I backed the screws out with my fingers. Give it a try, and hopefully all you'll need is a couple screws.

Ross..

[sledcrazyinCT]

The problem is they are JIS screws, Japanese Industrial Standard. They are not the same as a Phillips bit.


Maybe that why I don't care for phillips head hardware.....never knew about JIS? Is there a range of sizing like #1,2,3 for phillips?

[bkm]

Save yourself headaches and invest in a set of Vessel JIS screwdrivers. A set of 8 is around $80 or so. You'll thank yourself later. Dirtchrasher, I believe discovered this a couple of years ago on here and it has been a lifesaver.

Watch this video to see the difference between a Phillips and JIS


https://youtu.be/gEwVUZr5xxQ

[fieldy]

The problem is they are JIS screws, Japanese Industrial Standard. They are not the same as a Phillips bit.

I will try to drilling them later today. Now since we are on the subject, are the jis thread pitches the same as what you buy at like Lowes or Menards or are they special too? The metric hardware i have used from these stores seems to work ok. An online harware store is probably much cheaper.

[atc300r]

I drill all the screw heads off when they don't come out. I replaced the screws on my 200x with Philips standard head screws from the hardware store . I took the old one with me and matched the threads. I also had a screw twist off flush in the front mastercylinder. I built up a bead of weld and removed it with some visegrips. When you drill the heads off the screws pull the resivore cup off and carefully remove the threaded part use heat if you have to.

[fieldy]

Yes i had picked up some screws that should work if i can get these out. I noticed the tapered head part is slightly different. I had picked up some screws also for the chain sliders and the tapers are different. As long as i can buy cheaper hardware than OEM that will work, i will. Those slider screws were obviously not phillips. You could see the difference very easily.I will use a little antisieze on anything that i feels appropriate. I dislike that messy stuff, always wear more on me than i apply, lol

[Dirtcrasher]

I replace those 4mm screws with S.S. 4mm x ?? long screws with a flat head allen head from McMaster.....

[atc300r]

These are the screws I used they are larger diameter and flat on bottom.231116

[fieldy]

Im taking my time drilling, think i may need another bit. The master is nice and dont want to mess it up. These screws are tough and wont break. If i drill to far i might not have anything to get ahold of once the covers are off. Probably work on them next rainy day. Thanks to all.

[fieldy]

Well, 1 cover is off, nothing left to grab. Easy out is next step.

[fieldy]

Got two front covers off and three screws out, so far no damage. Soaking last screw with blaster till get away to the shed again. There wasnt much left to loosen but i used a sharp steel awl and made a dent in the top and side of the flush thread and beat that counterclockwise. Those were not frozen.
One master cylinder has a rotted rubber cover and red brake fluid. The other had a good rubber and brake fluid that looked and had the consistency of yellow grease.
I hope to find a master rebuild kit for these 86 tecates. Even if they work i want to rebuild them eventually. Thanks yous!

[fieldy]

Save yourself headaches and invest in a set of Vessel JIS screwdrivers. A set of 8 is around $80 or so. You'll thank yourself later. Dirtchrasher, I believe discovered this a couple of years ago on here and it has been a lifesaver.

Watch this video to see the difference between a Phillips and JIS


https://youtu.be/gEwVUZr5xxQ

I was checking out the JIS screwdriver sets above. I found that they were really nice but a little expensive and had only certain people who could import them. These things are like ivory or alligator hide. Some had to be imported and others were like a 6 piece set for around $30, probably not great. I kept looking and found that Dennis Kirk sells just the 1/4 inch bits. You get two bits for under $4, they have all 3 sizes of "phillips crosspoint" for under $12 bucks. They sell JIS special flat blade bits too. Thought that was cool since I've never had any special JIS drivers my whole life. I am going to order some.

[cobradude]

I've done 3 or 4 master cylinders by drilling them with a left handed drill bit. Once the bit hangs in the screw, it backs right out. Been replacing the screws with counter sunk ones with Allen hexes in them instead of Phillips.

It doesn't hurt to invest in a set of left handed bits, I got mine at the local NAPA store, was $30 for a set of 5, but they are GOOD stuff, carbide. I use them for a lot of stuff, my favorite is the stuck jets in carbs

[fieldy]

The KXT brake fluid resivoirs i have were missing the rubber diaphrams that go on top of the brake fluid and seal the fluid in. My question is can i just make a rubber gasket to bolt down with the cover and screws or is there another model part i can use because i can't find used or NOS. Well, i had found one for about $75.00. I would like to rebuild and use the origional 86 KXT brake setup.
Looking for any information, opinion or knowledge of crossover parts. I think i have seen the KXT master cylinder rebuild kits from Moose.
Then there is the ole "should i just use a modern dirt bike setup or aftermarket for the master and resivoir and which one?"

[fieldy]

84-87 KXT & KD 80.
Diaphram part number # 43028-1035