Reply
New member jks
New member

Re: 3126 Mechanical Aftercooler Core Presssure Test

Thanks,

 

Before I had your information, I had removed the Starboard Aftercooler (9 years old with 1000 hours Total).  I degreased it by circulating a cleaning fluid through the air side, descaled the fluid side with Ryd-Lyme, and then did a pressure test.

 

My setup was different in that I closed off the fluid inlet and outlet and pressurized the core to 60 psi (I had read in the service manual that the core had to withstand 35 psi of water pressure so I added some margin).  I monitored a pressure guage attached to the core (via one of the zinc plug fittings) and measured zero pressure drop after 45 minutes, so I concluded there were no leaks on the fluid side.

 

Based on your info, I will pressure test every year and probably replace at 10 years unless I find a leak earlier.  I also monitor Oil Samples annually which checks for any salt water in the Oil.  Hopefully that is good enough for pleasure use (100 -150 hours per year) rather than $5k to replace both aftercoolers every six years.  Hope I don't regret it given $$$ for engine repairs if the aftercooler fails.

 

Jon

Contributor

Re: 3126 Mechanical Aftercooler Core Presssure Test

Replacement of the Aftercoooler on the 3126 8NM 2 valve was not specified when this model was current. It was the later 3126E Electronic, C7, 3176C and 3196 which experienced durability issues with the aftercooler cores and as a result and to reduce the chance of subsequent engine damage Cat made the recommendations to replace at specified times   

New member jks
New member

Re: 3126 Mechanical Aftercooler Core Presssure Test

Thanks,

 

That was the info I was looking for.

 

Jon

Contributor

Re: 3126 Mechanical Aftercooler Core Presssure Test

Pressurise the core with 30psi air pressure. Submerge the core in water and check for the presence of bubbles indicating the core is leaking and must be replaced.

The core should be cleaned and tested every 1000 hrs or 2 years.

For aftercoolers that use sea water such as the 3126 then cat recommend replacement every 6 years.

Highlighted
New member jks
New member

3126 Mechanical Aftercooler Core Presssure Test

When performing a pressure test with air, what is the recommended test pressure?  Also, what is the maximum allowable leak rate (pressure decay over time)?

 

What is the CAT recommended service interval for performing this test?

 

Is there a CAT recommended service life for an aftercooler that is not leaking or otherwise defective?

 

Thanks,

 

Jon