Odor when using Pacbrake(Exhaust Brake)

[irishguy]

Hello All,

I'm just wondering if anyone finds there to be an odour in your motorhome when using the Pacbrake.

We get an odour but it doesnt smell like diesel exhaust or hot brakes. It is more like a burnt rubber smell. Is that normal?

Irishguy

[iluvuk]

Originally Posted by irishguy

Hello All,

I'm just wondering if anyone finds there to be an odour in your motorhome when using the Pacbrake.

We get an odour but it doesnt smell like diesel exhaust or hot brakes. It is more like a burnt rubber smell. Is that normal?

Irishguy

I don't get any odor.

[irishguy]

Darn, not an answer I was hoping for.

[guardrail53]

I would look in the close area around the Pac-Brake, make sure all the rubber hoses, lines are shielded and protected! May have had a wire tie break, and let a hose get too close! Nothing is the Pac-Brake itself that is rubber!
Let us know what you find? Rail!

[irishguy]

Originally Posted by guardrail53

I would look in the close area around the Pac-Brake, make sure all the rubber hoses, lines are shielded and protected! May have had a wire tie break, and let a hose get too close! Nothing is the Pac-Brake itself that is rubber!
Let us know what you find? Rail!

I hadn't thought of that...I'm going to have a look. Does the pacbrake get really hot when in operation?

[guardrail53]

Originally Posted by irishguy

I hadn't thought of that...I'm going to have a look. Does the pacbrake get really hot when in operation?

Heck yeah it does! It closes off your exhaust! I would not want anything rubber very close to it at all! Rail!

[nodine]

Originally Posted by irishguy

Hello All,

I'm just wondering if anyone finds there to be an odour in your motorhome when using the Pacbrake.

We get an odour but it doesnt smell like diesel exhaust or hot brakes. It is more like a burnt rubber smell. Is that normal?

Irishguy

you need to immediately open the bedroom access to the engine and look for insulation, hoses, wires, or any material that might have fallen down on the exhaust brake or engine exhaust manifold. The temperature of the exhaust manifold and the exhaust brake will go up when the exhaust brake is applied.

Bob

[iluvuk]

Originally Posted by nodine

you need to immediately open the bedroom access to the engine and look for insulation, hoses, wires, or any material that might have fallen down on the exhaust brake or engine exhaust manifold. The temperature of the exhaust manifold and the exhaust brake will go up when the exhaust brake is applied.

Bob

Agree. Let us know what you find in there!

[palehorse89]

Check the entire exhaust manifold closely, for "Black Soot" and crack's in the manifold........

[MSHappyCampers]

I wonder if the seal around the bedroom engine access port is bad. No matter what's happening under there you should not be smelling it in the coach.

[irishguy]

Thank you all.

I decided to have the experts check it over so I took it to a local truck service centre that I have used before and I trust.

I hope it's not the exhaust manifold. It had a new one installed just 2.5 years ago by the previous owner as a condition of sale.

I will keep you posted.

Irishguy

[TonyMac]

Originally Posted by nodine

The temperature of the exhaust manifold and the exhaust brake will go up when the exhaust brake is applied.

Bob

The engine is producing its least heat with the foot off the accelerator and the exhaust brake on. For the most part, no combustion is occuring. There is heat from compression, but that's nothing compared to wide open throttle and climbing. However, pressure before the exhaust brake goes up with the exhaust brake applied. I would look for a leak before the exhaust brake, look for the soot telltale. Look from the head to the exhaust brake for things that could produce that smell. Pressure downstream of the exhaust brake is negligible with the exhaust brake on.

[dennis45]

Originally Posted by nodine

you need to immediately open the bedroom access to the engine and look for insulation, hoses, wires, or any material that might have fallen down on the exhaust brake or engine exhaust manifold. The temperature of the exhaust manifold and the exhaust brake will go up when the exhaust brake is applied.

Bob

If you take your foot off the throttle to activate the exhaust brake it cuts the fuel supply to the engine. Right?
So if that's the case how does the temperature increase?

Does your campfire get hotter if you pull the logs off? Just asking.

[irishguy]

Originally Posted by TonyMac

The engine is producing its least heat with the foot off the accelerator and the exhaust brake on. For the most part, no combustion is occuring. There is heat from compression, but that's nothing compared to wide open throttle and climbing. However, pressure before the exhaust brake goes up with the exhaust brake applied. I would look for a leak before the exhaust brake, look for the soot telltale. Look from the head to the exhaust brake for things that could produce that smell. Pressure downstream of the exhaust brake is negligible with the exhaust brake on.

If there is a leak from the exhaust brake or the manifold wouldn't it smell like diesel exhaust? It is more of a burnt smell. It quickly dissipates as soon as the pacbrake deactivates. I have three carbon monoxide alarms in the coach and none have activated.