mystery plumbing

[tommy]

While removing parts from the firewall of my M38A1 , including the air cleaner I discovered two 3/16" , I think,copper tubes attached to the cleaner. They go towards the rear of the vehicle. What are they for? Thanks

[Jim]

They are part of the fording system, and provide
cleaned air to portions of it, probably the brake
master cylinder and transmission bell housing. Your
manual should have the full details of which goes where
and does what. The military at the time was enamored
with fordability as a contingency measure.

Jim in Darkest Arkansas

[wesk]

Hello Tommy,

The military has always been a fan of deep water fording. The interest began well before WWII and many of the system ideas used through the 50s and on originated in the WWII experiments. All tactical military vehicles through today have the ability to at least operate in 3 feet of water. This is accomplished by mechanically sealing those parts of the vehicle that cannot function well when immersed in water. Namely the engine, fuel system, brake system, drive axles on some, gear boxes and electrical components.

These items are usually taken care of by on board from the factory closed ventilation systems and electrical equipment water proofing.

Deep water fording represents taking the vehicle much deeper, above the windshield in many cases, by in the field addition of snorkels and exhaust extensions.

M38's came originally from the factory with the early WWII style water proofing and ventilating system. In 1952 they added a more elaborate system. This system continued in use until the second year of M38A1 production when as a cost saving measure the Army had Willys stop installing the basic ventilation system fording components. These were then installed in the field when the need arose. Don't confuse field installation of factory type ventilating components with the field installation of the deep water fording kits. Two separate issues.

With that said the components of your system are well illustrated in the later ORD 9 and the TM 9-1804A (Engine & Clutch) page 109 thru 113 for the M38 and the Ord 9 and TM 9-8015-1 (Engine & Clutch) Pages 148 thru 158 for the M38A1. The M170 missed out on most of the fording equipment.

Also Bob Westerman did a very good writeup on it for the CJV35 and M38 jeeps on his CJ3A Page.