What’s the proper air pressure to run with the air assisted brakes on a 404? I just got mine working and the gauge pegs out at 10 kgcm. I think that’s about 140psi? Could be more for all i know. I took apart the regulator, cleaned it all out, but it still wont regulate it any lower. What pressures are you guys looking at?
This system is pretty elaborate with several 2/3 way valves. There could be a valve that is simply not operable. Rebuilding the entire system may be your only option. I found this to be the case with mine and have since removed. Some of the seals on mine had become very britle and I wasn't able to find a replacement. Maybe someone will chime in with a source. The manual doesn't give any PSI ratings. Do you have any fluctuation at the gauge when you hit the pedal? If you need the circuit layout of the system -let me know... Good Luck
No fluctuation. I start the truck and it steadily rises till it hits 10. I thought the regulator vented to atmosphere when it hit its target pressure???
I’m going to install a 150 psi relief valve on the bottom tapping of the tank till I get this figured out. God only knows how much pressure builds up in that thing!
I’m going to install a 150 psi relief valve on the bottom tapping of the tank till I get this figured out. God only knows how much pressure builds up in that thing!
If it's the same vee-belt drive compressor as used on the later trucks, it has a lot of delivery volume but I don't think it puts out the pressure of the crank-driven compressor on a OM352.
The first component downstream should be the pop-off regulator and it's adjustable a little bit. It's probably gummed up.
For the 404 the manual states that the pressure regulator should cut out at 5.3 kp/cm2 (about 5.3 bar or 76.8 psi) for the single-curcuit (boosted) system. This is consistent with the operation of my 404 which has a factory brake booster. My air runs at 75 psi. For the dual-curcuit system (trailer air only), the regulator should cut out at 7.2 to 7.35 kp/cm2 (about 7.2 to 7.35 bar or 104.4 to 106.6 psi). Hope this helps.
I took apart the regulator, cleaned it all out, but it still wont regulate it any lower. What pressures are you guys looking at?
Linear Mode
