Husky - H1504st has too much back pressure?

by Evan Hearn
(El Dorado, Kansas, USA)

Hello...I have a Husky - H1504st that I have recently replaced the piston ring and belt, and now it will not pressure up past 35-40 psi before it starts to smoke the belt. Is there a way it might be getting too much back pressure?

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Dec 17, 2017
Any resolution
by: Jim

I am having this problem as well with H1504ST. Motor starts to labor, makes straining sound and stop with belt starting to burn. With valves open runs fine but of course won't build pressure.

Jan 19, 2017
Retired now handy man
by: Chuck Meyer

Evan/Bill,did you ever get this problem resolved? I am having the exact same problem. First started boging down at 80 PSI then the belt began to smoke. Now I can't even get 25 PSI and the same happens. The tanks have been drained and the check valve removed, cleaned and replaced. Still the same issue. If your problem was resolved please give me any advice on what resolved it.

Jun 23, 2016
Not building pressure
by: Bill

Are you saying that the compressor pumps the tank pressure up to 100 PSI, and then the compressor continues to run, and the pressure in the tank goes no higher than 100 PSI?

Your original post says that it would only build to 35-40 PSI and then the compressor would "smoke the belt", suggesting that the motor was good, turning the pulley, and that the pump pulley could not turn and that's why the belt smoke.

OK, you've got it up to 100 PSI now through disassembling and reassembling. This is good.

According to the specs this compressor should reach 155 PSI and cut out.

Based on what you have posted and the results obtained so far, I still think there is an issue with the pump.

When it stops building pressure at the 100 PSI level, does the motor labor at all? Is there any sound change? Have you resolved the issue with the burning belt?

I'm thinking that if the compressor is not laboring, then you've now got a gasket letting go at 100 PSI and air is circulating in the pump rather than being driven into the tanks.

Jun 22, 2016
Im at a loss...
by: Anonymous

Well...made sure everything was put together correctly, installed the new belt and now it will build to 100 psi and quit building pressure...Im at a loss here. Check valve is clear, new belt, new piston ring,

I have built up pressure and then released the drain valves (clearing the crap out of the tank )...I can't think of anything else to do. Ideas?

Jun 15, 2016
Back Pressure....
by: Anonymous

Well it is very possible. I tore it down (valves and all) today and cleaned everything up, reassembled and ended up burning the belt again and it broke, so now I am ordering another one. I will check the valve plate again and get back with you. Thank you for your time and I will give you my results as soon as the belt comes in! Thanks again!

Jun 15, 2016
Husky back pressure
by: Bill

Well it certainly sounds like it, Evan.

The first thing that comes to mind is that it's a valve problem, and I wonder, since you had torn it down to replace the piston ring, is it possible - and assuming it has one - that the valve plate was installed upside down? That might account for it.

Also, if your compressor was sloshed around a lot while you were working on it, it is possible that tank debris has fouled the tank check valve and just maybe it's not allowing free flow of air into the tank.

Maybe you could check these and let us know?

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