Air Tank Pressure

[desertdeals69]

My air pressure pegs the gauges.  Safety valve (150psi) is releasing air.  Where is the regulator?  I'm broke down in a Lowe's parking lot in Cookeville Tn.  1998 Freightliner ISB, Fleetwood Discovery.

[wolfe10]

The d2 (air regulator) will be close to the on-engine compressor, connected by air lines.

https://www.4statetrucks.com/air-electrical-safety/semi-truck-d-2-governor-bendix_6431.asp?gclid=EAIaIQobChMIm_jqg9331QIVC1d-Ch16-grsEAQYASABEgIoL_D_BwE

Any parts house that caters to OTR trucks will stock them-- under $25.

[rsbilledwards]

I carry a spare just because this happens and it happens to truckers all the time. It happens most often to rigs with out a moisture purging device that works automatically. The regulators are very inexpensive 

[desertdeals69]

5 hours ago, wolfe10 said:

The d2 (air regulator) will be close to the on-engine compressor, connected by air lines.

https://www.4statetrucks.com/air-electrical-safety/semi-truck-d-2-governor-bendix_6431.asp?gclid=EAIaIQobChMIm_jqg9331QIVC1d-Ch16-grsEAQYASABEgIoL_D_BwE

Any parts house that caters to OTR trucks will stock them-- under $25.

Thanks Brett.  I found the reg on the intake side of the comp.  I took the top 1/4 inch line loose and started the eng and no air.  I can't tell where the line goes but there is one on the bottom edge of the dryer.  Took the line off and started the eng and no air out of the fitting.  Took the fitting out of the housing and cleaned out some small particles, put it back together and still no air when eng running.

I will call Freightliner in the morning.

[wolfe10]

Bruce,

I would start by just replacing the d2. 

[obedb]

There are two companies in Cookeville that sell truck parts, but both are closed weekends. Commercial Truck Parts has a limited website, but they look like a good choice. Still don't know how to transfer a url , but the site offers a phone number and operating hours. Take the regulator with you.

 

[elkhartjim]

You can call Freightliner Help Desk 24/7/365.  800-385-4357 You will need the last 6 of your VIN.

[jleamont]

DD, replace it in the am, as mentioned mark the lines maybe photo the line configuration with your phone and take the old one with you. There isn't much to them and they are prone to failure. I also carry a spare like bill does. Several resemble each other, with the correct one in hand should eliminate any confusion.

[desertdeals69]

I just talked to Freightliner and they seem to think that something is plugged up in the dryer as there is no pressure in the 1/4 inch sense line.

Thanks for all the help guys.

[wildebill308]

Good luck, keep us updated.

Bill

[rsbilledwards]

Yup with a drier it adds another dimension and but makes the regulators last longer. I added the drier to my coach. They do require some maintenance and in coaches suspect many are over looked. Joe what should the service interval be on a coach. I have one where the filter is a spin on unit. I forgot to ask when i got it.

 

B

[bm02tj]

I was told highway trucks yearly motorhomes every two 

I do mine every three years 

[jleamont]

RSBILL, I change mine every two years. Due again in 2018, last time I installed a remanufactured dryer assembly, The previous dryer appeared to be all original, including the desiccant .

Some genius built a wooden box around it and moved it back off the factory mount with a hole in the side of the box. I couldn't locate the dryer when we bought the coach, at the time it was 12 years old with 59,000 miles on it. I removed the box, put it back where it came from the factory and replaced the entire unit then. The only thing I could think was he didn't like the noise when it purges, and he was successful, you couldn't hear it purge, I swore it didn't have one.

[kaypsmith]

I had to replace the valve last May, the drier was fine, so I only replaced the valve.

[desertdeals69]

On 8/27/2017 at 11:48 AM, wolfe10 said:

Bruce,

I would start by just replacing the d2. 

Brett you were right, it was the D2.  What threw me off was that Freightliner told me the sense line came from the dryer, I didn't think that was right.  I was able to talk to a local truck repair shop and the mechanic knew all about the air system.  He explained how it all worked so when I did my test it pointed to the governor.  I bought one from them and installed it in their parking lot and it worked.  I went and bought a second one for a spare.  Cost was $11.25 each.

[desertdeals69]

23 hours ago, obedb said:

There are two companies in Cookeville that sell truck parts, but both are closed weekends. Commercial Truck Parts has a limited website, but they look like a good choice. Still don't know how to transfer a url , but the site offers a phone number and operating hours. Take the regulator with you.

 

Thanks for telling me about Commercial Truck Parts.  They had the knowledge and the parts.  What threw me off track was the misinformation that I got from Freightliner.  They told me the sense line came from the dryer and if I didn't have pressure there the dryer was plugged up.  Totally wrong.

Thanks to everyone for assistance with my problem.

[obedb]

Was gonna suggest that they do a bypass of the air dryer if that was the problem and a replacement was not in stock. Their website shows working on big trucks so I hoped they would be able to help. Great price for a governor. As Bill Edwards and Joe suggested, they do fail. Funny. I used to carry a spare when "big rigging" ,but I have forgotten my habit. Think that I am gonna get     a spare plus one. Happy that you are back on the road. 

[desertdeals69]

3 hours ago, obedb said:

Was gonna suggest that they do a bypass of the air dryer if that was the problem and a replacement was not in stock. Their website shows working on big trucks so I hoped they would be able to help. Great price for a governor. As Bill Edwards and Joe suggested, they do fail. Funny. I used to carry a spare when "big rigging" ,but I have forgotten my habit. Think that I am gonna get     a spare plus one. Happy that you are back on the road. 

I talked to David at Commercial Truck Parts and does he know his stuff.  The first thing he said is he never works on motorhomes.  I said I didn't want him to work on it but just explain how all the air lines go and which ones had pressure.  He did and I trouble shot my system and determined it was the D2 modulator.  20 minutes to change it.

Thanks

[wildebill308]

Glad you got it fixed.

Bill

[obedb]

Happy they at least took the time to help you. I understand why a lot of truck repair places don't want to work on RVs, especially Class A units. Limited access to engines and some (not all) uninformed owners. 

Truck tractors offer plenty of room underneath and just raise the hoog for engine access. Most things are easy to get to. I often wish I had looked for a Super C although probably scarce on the used market. The engine and chassis could probably be worked on most places. 

Yes Carl/ I would be willing to give the room taken up by the cab. Lived in a 5' deep by 8' wide sleeper for a lot of years.😉

 

 

[jleamont]

2 hours ago, obedb said:

I often wish I had looked for a Super C although probably scarce on the used market.

Thought the same until I drove one, Spring suspension in the front , the term "Shaken not stirred" comes to mind . I agree, they are much easier to work on and much more accepted in a truck shop environment.

[obedb]

Remember what I did for 46 years Joe. I would be right at home. Not all trucks ride alike. Have driven many after air ride showed up for drive axles and trailer axles that were amazing.