air to air leak

I noticed my water temp about 5 degrees higher than normal a slight loss of power, so I thought, this is probably a air to air leak. took it to the shop on the way home & sure enough, had 1 leak just above the turbo, where the rubber hose connects to the aluminum pipe, just spun the clamp 1/2 turn & re tightend . the hose & clamp was o.k. shop said the hose just got pinched. then he walked around to the dr side & grabbed the hose going from the air compressor to the manifold & said air is going thru the hose. then he opened up the oil filler cap & said put your ear near the filler tube. I could hear air. so he said he was going to cap off manifold & put a hose & filter on air compressor to draw outside air. has anyone heard of this procedure? any thing to be concerned about. he did not have the filter kit, so I will be picking truck up this morning after he gets one & puts it on.

 

it is a ser 60 detroit. 11.1 95' picked truck up just a while ago. shop said could be the rings in the compressor are allowing the air to pass thru & to the engine. he said this will not hurt anything & that's why there are kits for this. he said if I was to buy a new compressor, I should keep the filter sys as he has it, that way you never have to worry about this happening in the future. I am not sure if this rerouting of the air lines with the air compressor has any affect on the power loss or temp, or if he just wanted to eliminate the air going thru the engine. the hose leak was pretty large. at least you could hear & feel the air pressure around the clamp. I asked about hearing the rush of air thru oil filler tube & wondered is this why my filler tube is always pushed out against cab door? he said most likely. I was glad he did what he did. at least for now. I had no idea air was being pushed thru my engine. the filter kit. does look like it belongs on the compressor, or at least an alternative option.


if this should not be kept on please explain. if it does not matter where air to compressor comes from, as long at it is filtered, how would it hurt compressor? if plugging port in manifold & it is not being used to draw air, how does that hurt? listening to oil fill tube was like putting ear to a large see shell. real weird & unatural to hear air where oil goes. thr shop is a local shop. over 30 years experience. was mgr of w.w.williams detroit for years. he said no harm at all keeping like it is. looking forward to all opinions. thank you.

 

OH' and I do not have boost gauge. I just look at the temp & know my truck on my route, along with my weight & know my power range & when it is off. if it was not for the temp, I might have suspected an overhead is due, or something else. but temp increase with slight power loss, gave me the air to air fault.

 

THANK YOU.