| Author |
Message |
Carolina houndog (162.39.83.48)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 21, 2003 - 6:12 pm: | |
Got the engine back in my old mc7, and running great. Going around fixing air leaks and what have you and have a leak when the parking brake is pulled. Seems to be leaking in the spare tire compartment out of a square thing with two air lines going to it and what appears to be a threaded vent hole. When the park brake is pulled on it leaks from the vent hole until the gauge goes to 0 psi. Push the park brake off and she holds air like a champ. Can anybody shed some light. Also how many air tanks are on this unit?
Found 4 one in front of the rear axle, two behind the front axle, and one in the drvers area compartment. Drain enough water and oily gunk out of them to choke a horse.
Thanks |
Jack Conrad (Jackconrad) (204.193.117.66)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 21, 2003 - 7:12 pm: | |
Sounds like you may have a parking brake diaphram leaking on you rear axle. The air leaks through the parking brake diaphram into the service brake chamber and back through the service application valve in your spare tire compartment. To test for this, apply parking brake and loosen the service brake application lines on the drive axle brake chambers, one at a time. If you have a leaking parking brake diaphram, you will hear/feel air coming out to the service brake line fitting. Of course the air system must have pressure. For more help and a drawing of the DD3 chamber go to www.bendix.com/downloads/service_data_sheet/dd3-sd3.pdf Hope this helps, Jack |
carolina houndog (166.102.117.114)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, February 22, 2003 - 12:45 pm: | |
Thanks Jack
I'll check that out. sounds like whats going on
because the park does not hold either.
Great link also, very helpful.
many thanks |
FAST FRED (209.26.115.205)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, February 23, 2003 - 10:03 am: | |
IF you really get stuck there are dyes that can simply be added to the air systems alcohol jar.
The dyes will floresce with a black light & even a tiny leak is very easy to spot.
Sold in air cond places & some mechanics supplys to find many different type of leaks.
Should be one for air systems,
FAST FRED |
jmaxwell (66.42.92.25)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, February 23, 2003 - 12:12 pm: | |
To follow on FF's post, NAPA stores sell a dye kit w the blacklight gun and it has several different dyes available for diff. uses. Goes for about $80.00. Works good for tracing oil leaks but don't know about air. Just wonder if u couldn't use regular food dyes in mineral oil and any ole' black light to do the same. But, what if u have a dryer and no alcohol jar? |
Chuck Harris - PD4104 (207.172.11.147)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, February 23, 2003 - 4:50 pm: | |
I have to wonder what exactly will carry the dye to the point of the leak? In an A/C system, there is a continuous transport of freon/oil to all parts of the system as the A/C runs. This will physically carry the liquid dye.
In a vehicle air brake system, the air is passed thru several stages of tanks, each of which does a fairly good job of stopping any water that might be in the air. Further, I am not aware of any gaseous dyes, which is what you would need here.
I have a TIF8800A combustible gas leak detector. If one were to fill the air dryer with alcohol, as suggested by FF, and make sure the entire system was filled with alcohol vapour, the TIF8800A would easily be able to sniff the alcohol vapour at any leak.
-Chuck |