Air Throttle Line size??

Paso One · January 01, 2011, 04:34:47 PM

I seem to remember someone recomending going to a 3/8 inch line from front to back.

I have a Williams WM 90 DX Throttle the ports coming out of it are 3/8ths

The copper lines I installed from the Firewall to the V730 and to the throttle slave cylinder on the Governor are 1/4 inch.

Apparently the throttle response is better with the larger size???

I'm going to pick up the DOT Plastic line and fittings soon what is your recommendation or what size are you using??

Eagle Andy · January 01, 2011, 04:59:17 PM

Paso one , I installed mine with 1/4 front to back from peddle and 3/8 from peddle to air supply , and my throttle works just fine with very little lag time . fwiw

pipes · January 01, 2011, 07:05:38 PM

When I was installing the air throttle. I plumbed it to the shop compressor 3/8 hose before
running the airline on the bus.Testing it would take 6 to 8 seconds to drop to idle. which caused the foot pedal to not exhaust quickly. too much air.. plumbed it with 1/4 inch.

Then that worked like it should. Ken

Oonrahnjay · January 01, 2011, 08:35:50 PM

I ran 3/8" line from the aux tank to the pedal and then from the pedal back to the cylinder on the fuel pump. Works like a charm. (Unit bought from Nimco, used.)

JackConrad · January 02, 2011, 05:34:42 PM

From these post, it appears that either 1/4" or 3/8" will work. We used 3/8" (per the installations instructions that came with the air throttle). Instructions also said the 2 lines from the tee in the engine compartment to the throttle actuator on the governor and from the tee to the modulator on the transmission should be exactly the same length. Jack

Paso One · January 03, 2011, 06:30:37 AM

Quote from: JackConrad on January 02, 2011, 05:34:42 PM
Instructions also said the 2 lines from the tee in the engine compartment to the throttle actuator on the governor and from the tee to the modulator on the transmission should be exactly the same length. Jack

Thanks everyone for your comments.

Jack I have heard of this before in likely one of your posts. This must be a "Service Update" As I removed the tee, copper lines from the donor bus and the lines are not equal from this factory installation. ( checked another bus as well )

I will however follow your recommendation of equal lines as it does make perfect sense. ( I know other air applications were this is re comended.)

I'm still undecided on the size but maybe since I'm going with the equal lines I should go with 3/8.

Sometimes I just wish some of this stuff was " cast in stone " so I didn't have to even think about it

Paul

Ericbsc · January 03, 2011, 03:13:07 PM

I ran 3/8 to both. First time had 20" longer on tranny and got funny shifts. Changed and all was well. Don't know if that was the problem but shifts ok now.