Airmaster compressor

[cranny]

Hi, i have an early 80s Airmaster AM15E P50 stamped on the model, serial no is 022876, its done really well over the years, but is starting to take ages to get upto pressure,What i was looking for is replacing the rings, but not sure where to get some, i tried my local Machine Mart but was not interested, said buy new compressor.
I removed the head and it has 2 different sized bores, does any one know what size rings i should be looking for to fit these bores.
thanks

 

[Tom O]

It’s best to measure them with a micrometer

 

[Seadog]

You need to measure the bore size at the bottom, where there is least wear. Then measure the groove width on the piston and the root diameter. Then you could approach a company such as this one to see if they can help - https://www.coxandturner.co.uk/

 

[not done it yet]

Are you sure it is not the valves that is causing your problem?

Will now go and hunt out the details of your compressor pump (there being no link to help).

 

[not done it yet]

As per Seadog. Making rings is not difficult. But still likely the valves are tired.

 

[Alan Reynolds]

I found rings on EBay for my very very ancient Broomwade. They wanted about £70.00 for rings from Broomwade and was less than £10 on Ebay. The leaf valves may have cracked or accumulated dirt under them. I’ve may valves out of feeler gauge strip of the right thickness.

 

[Seadog]

Another cause may be carbon accumulation. If it's run for extended periods then the head will get very hot. The problem is exacerbated by using the wrong oil. Motor oils with additives are not recommended.

 

[the snooper]

I'd start by checking if the cylinders are oval or any noticeable wear if ts had a lot of work, then as mentioned strip the head and valve plate clean it all up and all new gaskets don't be tempted to use the old ones, compressed air may be leaking straight back into the intake through a bad gasket

 

[Red'n'Black]

You need to measure the bore size at the bottom, where there is least wear. Then measure the groove width on the piston and the root diameter. Then you could approach a company such as this one to see if they can help - https://www.coxandturner.co.uk/

Excellent stuff. Bookmarked.

My old 1980s Clarke needs a stripdown and probably new rings, blows oil out the filler vent. No parts available from Clarke any more but these guys look like they should be able to help. Another job on the round tuit pile.