# vintage Pelton air compressor



## bernietech

I have just acquired a Pelton air compressor. It is powered by a 1/4 hp GE type KH motor. 115 vac, 4.3A, 1725 rpm. GEJ-435, 5KH-45AB55B. the single stage pump is marked1872E and has a rubber cap on it marked with a "W" and says "hubbard". the pressure switch is a square d 1500M12. the tank is horizontal about 10 " dia and about 20 " long. painted flat black and appears to be original. the tank has four welded feet on it. the tank has a tag "Pelton Detroit USA". I will try to post photos tomorrow. any information will be welcomed.

thanks

bernie


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## bernietech

just took some pics and will try to insert them here. the tank is 19" long and a 10" diameter.

hey it worked!!!

thanks for iny info

bernie


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## 89yt12

cool compressor


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## bernietech

thanks. before i run it an oil change is in order. i used it for about 10 years to blow dust out of computers in a high school. when i retired it sat for 4 more untill i saved it from the scrap man this past week. they are building a new school and many thing have to go before the move. wish i knew more about it. pelton makes dental equipment, somehow i don't that is what it was made for, unless it was for an elephant dentist!!!!

bernie


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## Johnny Spimony

bernietech said:


> I have just acquired a Pelton air compressor. It is powered by a 1/4 hp GE type KH motor. 115 vac, 4.3A, 1725 rpm. GEJ-435, 5KH-45AB55B. the single stage pump is marked1872E and has a rubber cap on it marked with a "W" and says "hubbard". the pressure switch is a square d 1500M12. the tank is horizontal about 10 " dia and about 20 " long. painted flat black and appears to be original. the tank has four welded feet on it. the tank has a tag "Pelton Detroit USA". I will try to post photos tomorrow. any information will be welcomed.
> 
> thanks
> 
> bernie


That's an awesome looking compressor very nice work!


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## bernietech

just tore the unit down. not much more info. #"66" or "99" stamped on top of compressor head. the belt is marked "pelton-model h", must be original. no other markings of any kind. no results on internet searches.

bernie


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## bernietech

just an update. upgraded motor to 1/2 hp, jumped pressures switch to get above 40psi. now going to 60 psi, the limit of my gauge. removed the air intake filter, a pack of 1/4 " oiled felt, interlayered with oilled paper. it had a reducing washer so the air intake was reduced from 1 1/4" to about 3/8" diameter. think I'm going to take the head off and see what I have. I bet leaks as it takes forever to build up any pressure. pump is running around 700 rpm as a educated guess using pulley ratio and a motor speed of 1725 rpm driving a 3" pulley with a 71/4" pulley on the pump. the original 1/4 hp motor had a 2 1/4" pulley. down the road, if i can find and correct any internal air leakage, a new pressure switch, 200 psi gauge, a safety valve and check valve if needed. any thoughts out there???

bernie


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## bernietech

just pulled the head. pics attached.


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## bernietech

I cleaned the reed valves with brake and carb cleaner, made a new head gasket. assymbled with two thin coats of permatex #2 non-hardning on the gasket. now I am tracking down plumping leaks with soapy water. how long should it take for a tank to leak down? in an ideal world ther should be no leaks and the tank pressure should stay at a level indefinately. what is an acceptable level of leakage? I know I still have some known leaks to fix. with tank at 100 psi it dropped to 80 psi in about 2 hrs. overnight it dropped to 10 psi in 14 hrs. 

thanks 

bernie


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## cedgo

Was a pipefitter in an earlier life. When I put my home system together, and I ran air lines several places, I vowed to have no leaks. Didn't happen. Seems no matter what you do, there's going to be some bleed-off. 
However, your bleed-off seems to be a little excessive.
Usually at the end of the day, I just shut the main valve on the tank off. 
Pressure will stay pretty much indefinately.


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## bernietech

i"m getting closer. got it pumping up to 120 psi in about 15 min. after shut down it is holding pressure a lot longer. after 28 hrs it is at 45 psi. tightened all fittings and replaced gate valve with a ball valve. this i am happy with, as I only use it occasionally, and plan to drain tank down after most uses. not bad for only putting 50 bucks into it. most of which was for a new pressure switch. the rest for a few pipe fittings, check valve, over pressure blow out valve and gauge.

bernie


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## bernietech

help!!!!! the last time i fired up the pelton it ran great (about 3 mos ago). last week I needed some air and no pressure. I pulled the head off and noticed some permtex #2 on the piston. (I used it on the head gasket). cleaned everything with brake cleaner and carb cleaner. cut a new head gasket and reassembled with no permatex this time. still no pressure. pulled the line from the pump and ran, no pressure. my thinking is the pump has a ring problem and the blow by is causing the symptom of no pressure. I think the next step is to pull the pump pulley, drain the pump of oil, and remove the bolts I see around the crank shaft and see what happens. I have never pulled a pump apart so I don't know what to expect. any thoughts out there??
thanks,
bernie


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## rhenning

If you had Permatex on the piston you probably have some holding one of the valves open. Roger


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## bernietech

I agree. I did clean the reed valves, better than I did on the first rebuild. I will pull the head off again(only 4 bolts) and clean, easier than tring to get the piston out to check the rings. but I think that is is my next step.


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## bernietech

pulled the head again. still clean and in order as best as I can tell. put it back together and still no go. I may cut another gasket and install 2, one on top of the other. It could be to thin, as the original may have been thicker. if no difference then i think it is ring time.

bernie


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## jow

Without looking back on comments, can you isolate the tank with pressure sealed in it? This would allow you to test the tank for pin-holes etc. I have a 40 yr old hole in the bottom with the same self-tapping screw and O-Ring solving the leak. A friend suggested leaving it open to allow the moister to drain (since it d/n affect working pressure). Plus, the unit is not left on and used approx monthly.


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## jow

Sorry for the out of sink post. I d/n see to go to the last post of the 2nd set vs the 1st. Good Luck on checking the rings. I feel you could do something related to a compression test on a combustion engine. Without a plug hole, I feel my rule of thumbs test should give you some indication of workable compression. In testing for bad rings w/o a gauge I learned that I c/n hold the compression on the cyl with my finger or thumb in small engines. Usually that would be less than a reasonable 90–100 psi. 

Rings w/n just wear instantly but sticking due to etc could be an issue. Ring gaps should be spaced around the cyl vs in a line or close. A thicker head gasket w/n help IMO unless you d/n have good flat mating surfaces.


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## bernietech

found about 2 hrs today to play. thisis how i used the time. soaped up the head gasket and let the pump run. after a few mins i was making bubbles from several places around the head. the 4 head bolts were as tight as I wanted to torque them.

at this point i pulled the head and cleaned it again. crocus cloth on the machined head surface and the brass plate which is separated by the head gasket. cut a new gasket and put it back together again. ran it again and still tiny bubbles.

does anybody have any ideas as what to use for gasket material? any suggestions for a gasket sealer. when i first did this i used permatex #2 and it worked . currently i am cutting gaskets out of felpro rubber-fiber (oil, water , gasoline) part # 3157. i am thinking i should use another gasket material, but what?

thanks,

bernie


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## bernietech

had a little time today. pulled the head and cleaned everything. reassymblied after using oil on gasket to help seal. no bubbles, but no pressure either . I think i will double up on gaskets and see what happens. 

on another note (just in case ) i bought a spare compressor pump on line. nos riverside (monkey wards) in mint condition. I have a spare motor, so I will plumb to the existing tank and use it.

bernie


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## shanonmethod

bernietech said:


> just took some pics and will try to insert them here. the tank is 19" long and a 10" diameter.
> 
> hey it worked!!!
> 
> thanks for iny info
> 
> bernie


That's nice.I admire the upper motor connector.


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## lhfnfj

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