used Coltri Mch-6 oil dipstick tube

[luskateer]

Hi,
i have a used Coltri Mch-6 i think. No placards on the unit. I ran it up to 2500 filling a tank and turned it off. Air was escaping from the dip stick . It also seamed hot..... Is this some kind of blow by.... or bad rings. I haven't changed out the oil yet. Don't know if it's synthetic or regular. I'll try to up load some pics soon.
thanks
rich
p.s.
I've gone back to it and with the machine off i load it up with 2000psi of air and i can hear it bubbling up in the crankcase oil.
r

 

[rcontrera]

First suspects are the valves. Get those inspected and changed out. There is a 100 hour service kit that includes the valve plates, springs and seats for the 2nd, 3rd and 4th stages.

Then inspect the piston/cylinder. The only cylinder under the surface of the oil is the forth stage but it doesn't use rings so pressure leaking from the other pistons would still bubble through the oil a bit.

As for oil, just plan on shifting over to synthetic while you are working on it. You should also buy enough to do several oil changes ... the whole cleaning thing ... in case you had mineral oil in it in the past.

 

[luskateer]

So i've started taking things apart. It's my nature and i have the 4 stage off. I'm having trouble getting the top off of the cylinder though. Can i heat it with a torch to help removal. It's a hex head like bolt. I'm assuming it will come with enough persuasion.
And under it i should find a valve......
I think i'd like to get the 200 hour kit to bring this unit up to speed. I'll be ordering some stuff from you soon. Any advice is always welcome.
Rich

 

[luskateer]

Opps! musta clicked twice

 

[rcontrera]

From your pictures it show that yours is at least 15 year old because 1995 is when Coltri went to a different style of inlet filter. That also means that your 4th stage head has a JIC style connection. both of those little tidbits are important if you are going to order parts so you get the right stuff. In addition, you may have a first stage valve plate with metal valves and now they use a reed valve plate.

Be careful when you are trying to turn the 4th stage head out of the cylinder. You don't want to damage the cylinder. A little penetrating oil may be called for and a smack or two.

When it does come loose, you should find a very thin spring and a small plate underneath ... the valve. There will also be a copper gasket ... remove that if it stick to the cylinder. You get a new one with the 100 hr kit.

I put a parts breakdown below so you can see what it looks like inside. It is actually a very easy machine to work on in that it is simple and everything is fairly intuitive to the mechanically able.

 

[luskateer]

Thanks for info and diagram.
What all comes in the kit....and aren't there two ...a 100 hour and a 200 hour kit.

I got the 4th stage off o.k. but am struggling with the head bolts on the 3rd stage. i plan to use an impact twister, the kind you smack with a hammer and it will torque the bolt loose. I've also been putting heat to the bolts when i can get to them.
Having way too much fun with this project.
Should i be using blue locktight when i reassemble?
or should i be using neverseize.
Rich

 

[rcontrera]

I use teflon grease on the threads.

The 100 hour kit has 2nd, 3rd and 4th stage valve plates and springs, 2nd and 3rd stage valve seats, 4th stage head, gaskets and inlet filter. You will also need to get the updated filter housing for your compressor as well.

The 500 hour kit also includes the first stage valve reeds, valve plate and first stage gaskets.

 

[luskateer]

So i have most of it apart. I think what i want is the 100 hour kit....plus
synthetic oil for a couple of changes.
filter for this system(sc000340)
four head bolts for the 3rd stage.
Rings for the 3rd stage.(top 2 are broken)
springs for the 2nd and 3rd stage.
There's a paper head gasket for the 1st stage???? needs replacing.
"O" rings for the 4th stage ....these may come in the service kit.....

The connecting rod wrist pin # 3 fell out and i don't see an easy way to get it back on short of opening the case and inserting from the inside ......any thoughts on that.
thanks for the help.....
rich

 

[luskateer]

Up date on the rebuild.
I removed the fan side plate from the case and see that the insertion of the wrist pin in #3 should be easy. Just waiting on some info on the rings and springs and i can move forward with the job..

 

[jkaterenchuk]

I would also suggest you get a snorkel (hose) to allow for the intake filter to be placed far away from the exhaust of the gas engine. Right now its took close for comfort and you would not want any CO surprizes at depth underwater.

John