# HF 62765 29 Gal. Compressor Won't fill past 80 PSI



## fletchbzmmt (5 d ago)

So I trying to figure out what the next step might be... my compressor ran for several days as it's in a detached garage. The pressure switch would not turn off the compressor I had to unplug it to get it to stop. I tried plugging and unplugging it many times but it wouldn't turn off if it was plugged in. Left it unplugged for several days and checked it again and it seemed to be working, would turn off and on, other than it will not build pressure past 80PSI. (It was also doing this when it was plugged in... not building past 80PSI so it never turned off.)

I replaced the pressure switch with a replacement part from HF. Still won't build past 80PSI, so it just keeps running. No leaks I can see anywhere, I used soapy water etc. The next/only thing I can think of at this point is that it might have a broken or defective reed valve? 

Any help would be greatly appreciated. Thanks in advance.


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## sledman8002002 (Jan 28, 2021)

Welcome to the forum fletchbzmmt!


fletchbzmmt said:


> my compressor ran for several days as it's in a detached garage


It's worth checking the reed valves, tho I have a feeling the issue could stem from the wear on piston/rings as a result of the several days/hours continually running.
How is the oil level? Or is it an oil-free model?


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## fletchbzmmt (5 d ago)

Thank you for the warm welcome @sledman8002002 

The oil wasn’t low but did darken pretty badly. I changed the oil etc. It’s supposed to have thermal overload protection, but that might just be fore the electric motor I'd assume?
LoL I only know enough to be dangerous...

Ok I’ll check the head to see if it’s leaking there… it never occurred to me about piston and head. If not that I’ll check the reed valves.

I would assume there’s somewhere to buy a new pump, other than HF? Seems the model I have was made by Finni or something like that? I'm fairly handy and not afraid to tackle rebuilds etc as well. Does anyone know what comparison would be between just buying a new pump head vs. buying parts like new rings etc?


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## fletchbzmmt (5 d ago)

@sledman8002002 So I checked checked the head and gaskets... no sign of a leak. I did however check the air intake based on video's I'd watch to troubleshoot such things... it definitely seems to be having blow back coming out the intake. So, to me, this would seem to be a valving issue then? Is there anything I need to know about taking the head off before before I do it? By the way, this is the pump head I have. Again, tyvm in advance.


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## fletchbzmmt (5 d ago)

sledman8002002 said:


> Welcome to the forum fletchbzmmt!
> 
> It's worth checking the reed valves, tho I have a feeling the issue could stem from the wear on piston/rings as a result of the several days/hours continually running.
> How is the oil level? Or is it an oil-free model?


Sorry not intending to bombard you with notices, but wanted to make sure you got a notice that I had replied. i.e. wasn't sure if mentioning you on the forum would give you the same notice as just replying?


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## fletchbzmmt (5 d ago)

Well, I for sure blew a head gasket, and it seems the reed valves got pretty burnt up too... 

Top head plate.











Bottom head plate.













Pistons...












Head plate/top of head from underside...













The gasket blew out in-between the valves... the gasket material had been blown out and was visibly moved and burnt up. So... The piston heads and edges look solid, no sign of blow by on the piston heads. The cylinder walls also still look nice and smooth, no pitting or scratches etc. This is still a pretty new compressor that I bought in the last year. My current thought process is to get a head gasket reseal kit and replacement reed valves and put it all back together and see if it completely fixes the issue or not. I suppose I can always just buy a new pump head if it doesn't work. Anyone know where to get these pump heads replacement parts? 

Thanks in advance y'all much appreciated.


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## fletchbzmmt (5 d ago)

For someone who might in future be looking for parts on this thing in the future... well, they seem to be rare as hens teeth, at least as far as I can tell. I was able to find a part # through www.gtair.co.uk and it is the BS3800 Complete Service Kit which includes all the gaskets and reed valves. However, this business is in the UK and they want $50 as of this date for the kit plus $15 for shipping as well... plus shipping time from the UK. Same on Ebay seems like it was probably the same business. Harbor Freight does also have a 3HP and a 2HP pump head that will work on this compressor, however it's not a direct fit and some retrofitting will have to be done to make it work.

As far as my personal situation goes I called my local store to see if they might be able to guide me to a local compressor repair shop and while talking to them I was able to find that I still had a few days left on my standard 90 warranty <happy dance>... very nice helpful folks there at my local HF. They had a new one waiting for me when I got there and the paperwork already started. YES, I bought the 2 years warranty when I was there to cover the replacement unit! I will just keep in unplugged from now on to prevent this from happening in the future as it doesn't get regular use.


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## sledman8002002 (Jan 28, 2021)

fletchbzmmt said:


> Sorry not intending to bombard you with notices, but wanted to make sure you got a notice that I had replied


Hey, no worries fletch. I only get the notices on my desktop PC which I generally wont see until the mornings. I've no problem witht that at all.


fletchbzmmt said:


> it never occurred to me about piston and head


Actually I was referring to piston and ring wear due to the non-stop running. 
Great job with the pics during the teardown! Not surprising that the unit got hot internally. I meant to ask you if you could feel excess heat coming off the compressor when you discovered it still running.
I zoomed up on one of pics, the piston top here has some dings in the 3 to 5 oclock region, surprisingly the cylinder walls look OK. But there does look to be some scarring/grooves in the wall at the 8 oclock postion. Could be reflection off the piston top tho.


















The piston top scarring wouldnt bother me but I would be concerned with possible ring damage.


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## sledman8002002 (Jan 28, 2021)

fletchbzmmt said:


> For someone who might in future be looking for parts on this thing in the future... well, they seem to be rare as hens teeth, at least as far as I can tell.


Not unusual these days it seems. I'm not sure the kit you found will bring it back to proper running spec. I'd be inclined to straight edge the head as it now may have some warpage. A straight edge would tell you, also check the cylinder top for the same but I 'think' it came out OK.


fletchbzmmt said:


> I was able to find that I still had a few days left on my standard 90 warranty <happy dance>... very nice helpful folks there at my local HF. They had a new one waiting for me when I got there and the paperwork already started.


That is indeed great news, kudos to HF  Congrats, (you should pick up one of those billion dollar lottery tickets as well!) 


fletchbzmmt said:


> I will just keep in unplugged from now on to prevent this from happening in the future as it doesn't get regular use.


Yes, thats wise. I do the same but with a breaker on my panel when I enter or exit my shop.


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## stevon (Mar 5, 2019)

fletchbzmmt,

Glad you got it sorted!

Stephen


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