Air compresser's down

rooster · December 21, 2010, 10:54:31 AM

I have 2 compressers,
One gets to about 30 psi and wont build any more (keeps running), its been that way for about 2 year now.

The other one is a small backup, I found a small hole it the bottom of the tank, I can use it for small things, but im working it to death!

My question is can this be welded up or brazed? Any precausions?

enjenjo · December 21, 2010, 11:25:38 AM

The first one needs the valves rebuilt. not a big deal. Do not weld the tank!!!!It's rusted out and should be replaced. They can fail catastrophically. Put the compressor from the bad tank on the good tank with a bad compressor.

Talk to Santa.

Woody2B · December 21, 2010, 01:05:43 PM

Someone gave me a junk 5hp, 30 gallon one time. I thought I would give it shot since I wouldn't be out anything. They're easy to "refresh". Disassemble the compressor head and remove the reed valves from the plate. They typically get gunked up and corroded here. Use scotchbrite and carefully polish the reed valves and seat being carefull not to bend the thin reed valve or score it. I used a ball hone and gave the cylinders a quick pass or two to break the glaze and reseat the piston rings. Trace the head and valve plate to cut some new head gaskets from a sheet of Form-A-Gasket material. Clean it all up and reassemble with a new can of compressor oil. Total cost was $8 and mine will pump to 160psi with no problem.

Trying to patch a rusted out tank is big NO NO. Put the good compressor on the good tank.

rooster · December 21, 2010, 04:05:12 PM

Thanks for the info guys!

I actually have 2 of the LaPlante compressors I got them off ebay afew years back, The first one I got did the same thing so the guy sent me a replacement and told me to keep the old one. (thats a bad sign)

Ill take the 1st one I got and see if I can find those valves your describing.

http://laplantecompressor.com/

I found them on the net and got a email off to them for a parts manual.

wayne petty · December 21, 2010, 11:16:09 PM

rooster... how about a close up of the number plate on the end of the compressor...

i would also think... before i ripped the cylinder heads off..

that i would check the unloader....

the what..

??

the device that unloads the air pressure from the high side of the heads... so the compressor can start from a stop and get up to speed before building pressure...

prevents locked rotor sort of effects... HHHHMMMMMMMMMMMMMMM popp!!!

they are normally centrifical ... with spinning weights like a transmission governor ... when they spin and swing out.. they push a pin that causes the pressure to build...

you might also want to check the air filters...

and check the output tubes... i have found them cracked.. where the air from the compressor leaks before it gets to the check valve into the tank...

wayne petty · December 21, 2010, 11:31:08 PM

here is one of the air compressor manuals from leplant..

http://laplantecompressor.com/pdf/service/industrial/V120101-452-Manual.pdf

its probably for a different model....

but how they work... and the diagnostics will probably be the same..

here is one for their single stage model...

http://laplantecompressor.com/pdf/service/singlestage/LPS5138-Manual.pdf

knowing which model you have will really help.. just post the model number...

as for repairing the tank on the small compressor... bad idea..

if you need a tank... get one of the portable tire fill tanks... hook it up so you fill that one directly... but you will need a larger hose... try to find one of the tire fill tanks... with a threaded in fitting.. some are welded in..

or let the small pump... fill the big tanks...

rooster · December 22, 2010, 10:29:03 AM

I got the old one out of the attic last night, thay do look different than the links you provided. Havent heard anything from LaPlante yet! model number is

LPV553.

wayne petty · December 22, 2010, 12:03:54 PM

this looks a little closer... but it only shows the pump... not the unloader...

http://laplantecompressor.com/pdf/brochures/singlestage/LPV6546-SPC.pdf

still looking...

it the tank leplant also... is there a complete model number on the name plate of the entire compressor... or .. did you just get the pumps... and bolted them to your tank...

if so... how about some pictures of the unloader...

i wonder if LPV stands for low pressure V shaped cylinders as i also see W's in the model numbers...

since we are on compressors... this is the pdf for the pressure switches up to 175PSi...

http://www.hubbell-icd.com/icd/pressure/files/4269M_4269H.pdf

wayne petty · December 22, 2010, 01:01:56 PM

the last 4 pages of the manual i linked above..

http://laplantecompressor.com/pdf/service/industrial/V120101-452-Manual .pdf

show how the pilot valve... operates and is adjusted... start there...

rooster · December 22, 2010, 03:15:45 PM

I got the compressor a added it to the tank I had. I dont know what a unloader is! If that is the thingie that screws into the top of the tank here is a picture.

Kinda busy around here, doing some last minute shopping, of course I got the wrong thing and now have to return it,got some socket sets for my son, got home and checked his box, you guessed it!!!! got them last year for him. Running out of time. What a Zoo!

BAA HUMBUG!!!

jaybee · December 22, 2010, 08:41:45 PM

Probably. Where does the smaller line go? Some compressors unload by having the pressure switch blow down by opening a line that dead ends there.

rooster · December 22, 2010, 09:22:00 PM

Quote from: "jaybee"Probably. Where does the smaller line go? Some compressors unload by having the pressure switch blow down by opening a line that dead ends there.

The small line gos to the ele switch!

wayne petty · December 23, 2010, 12:21:40 AM

there still needs to be some kind of leak... so the compressor does not start against a head of pressure...

perhaps... they will supply a decent parts manual....

i went through most of the stuff i could find online from that company...

nothing on that exact model... other than the one page diagram...

all the others have a centrifical unloaders with a valve on the back...

is there anything on the flywheel side of the compressor.. or a small tube between the heads...

other than that.. time to pull the heads and do an inspection....

unless you can spin it up... shut it off and see if there are any places where there is a designed in air leak....

rooster · December 23, 2010, 01:19:12 AM

Quote from: "wayne petty"there still needs to be some kind of leak... so the compressor does not start against a head of pressure...

perhaps... they will supply a decent parts manual....

i went through most of the stuff i could find online from that company...

nothing on that exact model... other than the one page diagram...

all the others have a centrifical unloaders with a valve on the back...

is there anything on the flywheel side of the compressor.. or a small tube between the heads...

other than that.. time to pull the heads and do an inspection....

unless you can spin it up... shut it off and see if there are any places where there is a designed in air leak....

Maybe it leaks back to opposing cyclinder, just a guess! The compressor pictured has a broken head I will remove that and take a look. Here is picture of flywheel side.

Thanks guys

wayne petty · December 23, 2010, 02:34:07 AM

this is as close as i could find...

check page 13... looks really close...

so you kinda know what's hiding inside...

http://laplantecompressor.com/pdf/service/singlestage/LPV6546-Manual.pdf

i found it on this web page..

http://laplantecompressor.com/

but i went through every manual.. some are close.. with the fins on the head running a different direction... and a slightly different shape...

the factory parts sellers are listed in the dealers ...