Compressor finally died...rebuild, replace pump or buy new?

[ARAMP1]

It finally happened...I've had this craftsman professional 7 hp/60 gal compressor since 2005 and it finally died on me. Wouldn't build up past 90 PSI and was spitting oil all over the place.

There was a bit of a knock, like a rod was loose on the crank. Sure enough, here's what I see when I tear into it.

Sides of the cylinders/pistons are scored a bit.

Head gasket was trashed and there was A LOT of gunk.

I'm guessing one doesn't rebuild these. I was thinking about replacing the pump. The tank and the electric motor seem to be in fairly good shape. I figure I could get a nice pump (maybe 2 stage) for $5-600. What say the GJ crowd?

 

[koditten]

You could get a complete compressor for that kind of money. Keep the tank and plumb it parallel to the new tank and double the capacity. You could even put the tank in the attic if realstate was an issue.

I paid 6 and some change for my Kobalt from Lowes 3 years ago. I'm happy.

KO

 

[Megadodo]

My compressor seized and burnt the electric motor out! When I have funds I'm getting a new whole unit (only £50 more then replacing the motor and compressor) and use the tank from the old one as more capacity.

 

[CNGsaves]

Have you priced the parts for an overhaul kit??

Looks like you've got one bearing that was dragging a bit (crank needs polished up), and cylinder wall that will need honed.

Can't tell the shape of the valves . . . likely they would need replaced.

Since you've got it all tore down, I'd bet most of work is already done.

+1 vote to overhaul and repair the old Cman . . . give it a new life!!

 

[Burl]

If you could rebuild it AND turn it into a 2-stage machine, thats the way I would go.

 

[930dreamer]

Tough call on rebuilding the Craftsman pump, I saw this on the CK5 also.

 

[ARAMP1]

Have you priced the parts for an overhaul kit??

Looks like you've got one bearing that was dragging a bit (crank needs polished up), and cylinder wall that will need honed.

Can't tell the shape of the valves . . . likely they would need replaced.

Since you've got it all tore down, I'd bet most of work is already done.

+1 vote to overhaul and repair the old Cman . . . give it a new life!!

Ive looked into rebuilding it, which is do-able, but I'd have to turn the crank and get some kind of bearing spacer for the new rod. Pistons aren't available anymore and who knows if the walls will clean up. Just seems like I'll spend about the same amount of coin and would be able to get a new, higher flowing, 2 stage pump.

I saw this on the CK5 also.

 

[Davefr]

Are the major parts (ie rod and crank) broken or just scored?

It looks like a reed valve self destructed and loose chunks of metal caused the scoring. (same thing happened to my POS IR compressor). First of all this is obviously not an internal combustion engine and light scoring will simply reduce it's performance vs. render it useless.

If scoring is the main problem you see and if the top end parts like valves and gaskets are available and affordable I'd replace them and give it a try. So what if it takes a little longer to fill the tank due to the leakage. (my IR pump has a scored cylinder and I haven't noticed ANY difference in performance).

If the pump is damaged beyond repair your options are:
1. Replace the pump with HF Chinese pump (approx. $150)
2. Buy a higher quality replacement pump (approx $500, unfortunately price of pumps jumps up quite a bit if you don't want to use the HF pump).)
3. Buy a new compressor and sell this one for the tank and motor.

 

[BrianC636]

We have a "Air Compressor" place in the town I live in that only sells/rebuilds compressors.

Last week when I was in there talking to them about my CH refurb project, he told me if my compressor ever junked out he can get a brand new one for around 250 or rebuild mine (given no major damage) for around 100. He had a TON of parts laying around too.

I bought some gaskets for mine and it was pretty cheap, less than 7 bucks for 3-4 gaskets.

 

[ARAMP1]

Are the major parts (ie rod and crank) broken or just scored?

One rod and crank journal are pretty bad. I'm not so concerned about the scoring on the cylinder wall/piston.

I've looked and the best I can find is a new crank for $200, rods are $25 a piece, valve plate is $45, and the standard gasket kit is $60. That's without any new bearings or rings. I just can't bring myself to rebuild it when a new pump that flows twice as much can be had for just a few bucks more.

 

[AV tinker er]

You could get a complete compressor for that kind of money. Keep the tank and plumb it parallel to the new tank and double the capacity. You could even put the tank in the attic if realstate was an issue.

I paid 6 and some change for my Kobalt from Lowes 3 years ago. I'm happy.

KO

I like this idea or something similar.

 

[BrianC636]

One rod and crank journal are pretty bad. I'm not so concerned about the scoring on the cylinder wall/piston.

I've looked and the best I can find is a new crank for $200, rods are $25 a piece, valve plate is $45, and the standard gasket kit is $60. That's without any new bearings or rings. I just can't bring myself to rebuild it when a new pump that flows twice as much can be had for just a few bucks more.

Want the name/number of that place I spoke with last week? He may have something cheaper than what you've found currently.

 

[RECox286]

It seems to me that your estimate to buy a new compressor (not system)

is a bit high. Compressors are available for much lower than that. If you

just want to put a HF compressor on your system (easy to do) then you

are only into it for as much as $150. at most, and less when they are listed

on sale. Take a peek at McMaster and or Grainger, for comparison.

When the new replacement goes to lunch, maybe you will have a better

idea of what to do at that point in time. At least that is what I would

do, knowing that the compressor itself is the usually the weak link in the

system. Get the real worth out of what is left of the system you have.

Uncle Bob

 

[rsanter]

Don't bother with that. Either replace the pump or the whole unit
Yu can get the pumps at HF and they may be made right next to where a new CMAN pump is made

Bob

 

[ARAMP1]

Well, just picked up the two cylinder V configuration pump at Harbor Freight. Out the door for under $200. I figured it was cheep enough to give it a shot. And the SCFM @90 psig is about 50% more than the stock Craftsman pump.

It'll take some scrap metal to mount it since its bigger and a little bit of plumbing and a different pulley.

 

[Davefr]

Well, just picked up the two cylinder V configuration pump at Harbor Freight. Out the door for under $200. I figured it was cheep enough to give it a shot. And the SCFM @90 psig is about 50% more than the stock Craftsman pump.

It'll take some scrap metal to mount it since its bigger and a little bit of plumbing and a different pulley.

That's probably the most practical approach. I think those pumps are decent. Let us know how the retrofit goes.

 

[Fixnair]

You will need to increase the motor size also if you want to get all the air that new pump can make. Simply increasing the motor pulley size will overload your existing motor. That extra CFM does not come for free.

 

[Bricktopp]

I just did the same thing to my craftsman pro. Although I only have a 3 HP motor and went with the smaller HF pump it worked out great. Only work involved was a new mounting plate, different pulley for the motor to put the pump at the right operating speed, belt, and reroute the pump to tank line. You won't be dissapointed.

 

[Vettman]

Was in a similar quandry. I decided to rebuild my Ingersoll Rand pump (made in Italy). I've had the compressor since 1987 and it's served me well but it wouldn't build pressure beyond 50 lbs. The valve plates had worn out. The new piece was over $100.00 but it works like new, so I'm a happy camper.
The Harbor Freight pumps would have required re-plumbing.