Pacbrake

Pretty much everything on the bottom side of the coach: Steering, wheels, tires, brakes, suspension
TDJohn
Posts: 570
Joined: Sun Oct 27, 2019 11:34 pm

Re: Pacbrake

Post by TDJohn »

To add to what Brett said, your Cummins engine is likely still the old school mechanical engine, which is different from the electronic CAT engines that Safari started using in '96 (my guess is yours must have been a left over or a special order). In any case, most of the older units with the mechanical Cummins engine used a floor switch in front of the driver's seat in the area of where your left foot would be. They also used a red push button switch located on the left side dash, by the transmission shift pad. Pressing either one of those switches should activate the exhaust brake, and the transmission sequence, that was described by Brett. There should also a red light on the left side of the front dash, that lights up when the exhaust brake is activated. Be aware that even though the exhaust brake activation and sequence may work and down shift the transmission as designed, but if there is now air pressure, like from a failed compressor, the actual exhaust brake won't close, so you will get some slowing down from the downshifting, but you won't get the full braking effect if the exhaust brake doesn't close.

Does your coach have an air ride suspension, or does it have the small aftermarket air bags to assist the weakening VelvetRide torsion spring suspension?

I'm curious, what is the build date of your coach?
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
brstough2004@gmail.com
Posts: 14
Joined: Sat Oct 08, 2022 10:47 am

Re: Pacbrake

Post by brstough2004@gmail.com »

Wow!!

Thanks for all the responses!!

I will find the build date (can you tell me where to start looking?)

There is no electric signal to the "activator" on the engine exhaust. It is a pneumatic actuator. It looks brand-new!

There is a floor switch.

Yes, I have Air bags. Uncertain if they were added later or if they were original equipment.

I had been assuming that all the functions controlled by compressed air used a common air compressor: (You know what they say about "assume")
Air Horn
Air Bags
Pac Brake

I discovered that the air bags are independent from Pac Brake. They must have had a small 12VDC compressor mounted by the manifold that controlls individual bags

In going through the fuse panels, I see that one is labelled "Air Horn Pump", so I am going to start tracing the wire from that fuse to find the air horn pump!

I do not see any air lines coming from the front of the engine - where I would expect to find the air compressor (CDL - familiar just from "pre-trip inspections" - however it is difficult to SEE the "front" of the engine - if there is a compressor, it must be gear-driven and be located up there since there is not a belt-driven compressor.)


Just another question about the air-horn: How would it be "honked" Pull string/cable or button on the steering wheel?


Thanks again for answering. I'll get more familiar with the forums and maybe find other threads in which this might have been addressed..

Brian
TDJohn
Posts: 570
Joined: Sun Oct 27, 2019 11:34 pm

Re: Pacbrake

Post by TDJohn »

Brian,

The build date can be found on the factory sticker that shows the GVWR and tire size pressure, usually located between the left dash and drivers side front window.

The small 12v compressor is usually mounted on top of the transmission cross member. On my coach, that compressor feeds the Pac Brake, and air horns, I also have an auxiliary tank up front, for additional capacity for the air horns. On your coach it maybe different or similar.
On my coach the are horn is activated by the horn button in the center of the steering wheel. I would think yours would be the same, but Safari has tendency for weird exceptions. :roll:

Do you have a red light on your dash?
Does it light up when you try to activate the Pac brake?
The pac brake solenoid will only activate when the pac brake is activated while driving...

I will send you a private message, so check your inbox.
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
brstough2004@gmail.com
Posts: 14
Joined: Sat Oct 08, 2022 10:47 am

Re: Pacbrake

Post by brstough2004@gmail.com »

Thanks for the reply! Lots of good information!

Just received the new "compressor kit" - with tank...

Any suggestions as to how to get to this compressor to change it out?

I'm thinking (but not too seriously) about cutting an access hole through the bedroom floor!??!!

A more coherent thought is to pull the battery tray out as far as possible and try to sit up in the back of there for access - but the wires and hoses may prevent any usable access?!??
wolfe10
Posts: 225
Joined: Sun Oct 27, 2019 4:12 pm

Re: Pacbrake

Post by wolfe10 »

As long as you plumb in the compressed air lines to the "devices" they are currently connected to/designed to be connected to, where you locate the compressor is up to you.

I relocated mine to a dry location and ran the power through a relay with power directly from chassis battery positive with "ignition hot" as the "close relay signal".

I have seen Safari's with that compressor located above the rear axle in a dirty location-- can not understand that.
Brett and Dianne Wolfe
Ex: 2003 Alpine 38'. Ex 1997 Safari Sahara. Ex 1993 Foretravel U240
Moderator, FMCA Forums 2009-2020
Chairman, FMCA Technical Advisory Committee 2011- 2020
Moderator, http://www.dieselrvclub.org/ (FMCA chapter) 2002-
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