'87 DD 8V92 readings, sights and sounds

[KimnKim]

Bought my '87 about a year ago and have been re-doing the interior since. We finally completed to the point where we were able to undertake the maiden week long voyage as well as a short follow up weekend. So, with the first couple of drives under my belt, some relavance to a few baseline numbers would be appreciated from those of you whom have been soldiering with this workhorse engine for oh so many years. Ranges of some of the categories I was able to glean from the Detroit manual, but others I'm just not sure about.

Pyrometer temp ranged between 400 and 600 degrees (the later during a mountain pass climb). Transmission oil temp 180 - 195 degrees. Brake and coach air climbed to about 135 lbs. after several minutes at highway speed and pretty much lived there until we arrived back in the city (and into traffic again)...is this one high? The sneezer seems to be much less active on the highway than in city driving and I believe it sneezes at about 125 lbs. in city driving circumstances.

Also had an audible warning that seemed to be related to the air system, but not a low air warning. That alert, in my coach, is an after market buzzer that seems to work just fine (buzzes until 70 lbs are achieved). This warning is a chime that sounds much like sonar 'pings'. Had it not been for the need to activate the air horn, which triggered the end of the annoying alarm, it likely would have been a long while until I was able to narrow it to the air system, as this alarm is very intermittent. Could this be an excessive air alarm?

[fulltiming]

I envy your pyrometer. I wish that my Newell had a pyrometer. Your transmission oil temperature is normal. The brake and coach air pressures are high. The pressure relief (sneezes) at 125 is normal but once the pressure is relieved, the compressor should not continue to run further increasing the pressure. There is likely a large canister, probably on the driver's side of the engine compartment that says BrakeMaster (Model 68 CR in mine). That is the air dryer/pressure relief unit for the air system. Once pressure builds to 125-128 psi, the relief valve should open and the compressor shut down until the pressure drops to about 105-110 psi. You should have that situation looked at to see if the relief valve is sending the proper signal to the compressor.

The only chime that sounds like sonar 'pings' on my coach is the air leveling system and tag axle dump. If the air leveling system is in the level mode rather than the travel mode or the tag axle is dumped, I get that annoying alarm. I would doubt that there is an 'excessive air alarm' as I have never seen such an alarm. If you don't have a tag axle, the alarm is probably a malfunction in the air leveling alarm indicator.

[KimnKim]

Thanks Michael. Be careful of that 'pyrometer envy' syndrome. Had a closer look at my over-air situation this morning and it appears to be sneezing at 132 lbs and then relaxing until 100 lbs. I have the same BrakeMaster as you. I spoke with my mechanic about this today and he says that I should get it looked at.

Regarding the ping warning, it does seem to eminate from the same under-dash device as the 'level' and 'tag' warning, but just displays a different tone and cadence. I'm sure that, with almost everything else to do with mechanical mysteries, it too will reveal its source over time.

Kim
I envy your pyrometer. I wish that my Newell had a pyrometer. Your transmission oil temperature is normal. The brake and coach air pressures are high. The pressure relief (sneezes) at 125 is normal but once the pressure is relieved, the compressor should not continue to run further increasing the pressure. There is likely a large canister, probably on the driver's side of the engine compartment that says BrakeMaster (Model 68 CR in mine). That is the air dryer/pressure relief unit for the air system. Once pressure builds to 125-128 psi, the relief valve should open and the compressor shut down until the pressure drops to about 105-110 psi. You should have that situation looked at to see if the relief valve is sending the proper signal to the compressor.

The only chime that sounds like sonar 'pings' on my coach is the air leveling system and tag axle dump. If the air leveling system is in the level mode rather than the travel mode or the tag axle is dumped, I get that annoying alarm. I would doubt that there is an 'excessive air alarm' as I have never seen such an alarm. If you don't have a tag axle, the alarm is probably a malfunction in the air leveling alarm indicator.

[encantotom]

my brakemaster wasnt blowing off all the time right, so i bought a new blowoff valve kit. it was about 30 bucks if i remember right at fleetpride.

takes a little effort to install, but isnt that bad. i did a filter change and new gaskets myself on it last year, but had my mechanic do the blowoff when he was working on my ac compressor. after watching him do it, i could do it myself pretty easily.

it made it blow off consistently at about 125psi on the gauges now. was erratic before. the brakemaster cr68 is easy to get parts for.

later

tom

[JohnC]

KimnKim,

Your pyrometer readings appear low. I suggest cleaning and re-securing the connections.

400 degrees on a steep grade is very unusual.

300 to 900 degrees F is closer to the norm. On long grades at high altitudes I would tend to back-off the throttle and shift down based on turbo exhaust temps versus the water temp.

JohnC

[KimnKim]

Thanks for the heads up John. I have it tucked away for the winter already but will have a look at connections next spring.

Looking at your location, I'll assume that you are 'related' to the Newell factory? I had the opportunity to tour the plant on the trip back to Canada with my Houston purchased coach...really impressive and not at all what I expected. In this day and age, one tends to expect the cold and sterile stainlees steel look. Nice to see a company that just plain does great work in an environment that has looked more or lees the same, I'm guessing, for decades.

Kim
KimnKim,

Your pyrometer readings appear low. I suggest cleaning and re-securing the connections.

400 degrees on a steep grade is very unusual.

300 to 900 degrees F is closer to the norm. On long grades at high altitudes I would tend to back-off the throttle and shift down based on turbo exhaust temps versus the water temp.

JohnC