After market brake system

Some clarification here, please.

An exhaust brake is the entry level engine brake that coach manufacturers put on diesels. Engine brakes that operate the engine valve train to achieve back pressure are the next level, more expensive, more efficient.

Is your question about auxiliary brakes on towed vehicles, I'm confused, but that's not unusual:)

I see from your other post that we are discussing engine brakes not towed vehicles.

The exhaust brake is a device that will be installed in the exhaust piping immediately downstream from the turbo charger at the top side of the engine usually. It will have a small air cylinder that moves a lever attached to a flapper valve in the exhaust system to block exhaust flow and cause backpressure to slow the vehicle. This in combination with gear downshifts does a pretty good job. If you feel this is not working as expected Jacobs has updated the system with the PRX model(I think) that has received good reviews. Before investing too much though, I would check whether the unit is lubed and working properly, a DIY job if you're handy. Lack of proper maintenance is a major reason for complaints of lack of performance. Also the transmission downshifting is supposed to happen automatically, so check that as well.

jtfcons wrote:
Some clarification here, please.

An exhaust brake is the entry level engine brake that coach manufacturers put on diesels. Engine brakes that operate the engine valve train to achieve back pressure are the next level, more expensive, more efficient.

Is your question about auxiliary brakes on towed vehicles, I'm confused, but that's not unusual:)

I see from your other post that we are discussing engine brakes not towed vehicles.

The exhaust brake is a device that will be installed in the exhaust piping immediately downstream from the turbo charger at the top side of the engine usually. It will have a small air cylinder that moves a lever attached to a flapper valve in the exhaust system to block exhaust flow and cause backpressure to slow the vehicle. This in combination with gear downshifts does a pretty good job. If you feel this is not working as expected Jacobs has updated the system with the PRX model(I think) that has received good reviews. Before investing too much though, I would check whether the unit is lubed and working properly, a DIY job if you're handy. Lack of proper maintenance is a major reason for complaints of lack of performance. Also the transmission downshifting is supposed to happen automatically, so check that as well.

X2

Your ISC (or ISL) engine has the small air cylinder that is on top on the driver's side, and looks like a small screen door closer. It needs graphite (see below) lubrication. Using it frequently helps keep it operating correctly.

I stand corrected. Brett Wolfe is the expert here and apparently graphite is NOT the correct lubricant. Thanks Brett.

The PRXB is a PacBrake item, not Jacobs......Dennis

Fishinghat wrote:

Your ISC engine has the small air cylinder that is on top on the driver's side, and looks like a small screen door closer. It needs graphite lubrication. Using it frequently helps keep it operating correctly.

Actually graphite is not the correct lube. Correct lube posted on OP's exhaust brake post.

350HP ISC 8.3L engines have exhaust brakes and the 400HP ISL 8.9L use Jake Brakes.

Nomadac wrote:
350HP ISC 8.3L engines have exhaust brakes and the 400HP ISL 8.9L use Jake Brakes.

Agree on C which will have exhaust brake.

The L was offered with EITHER exhaust (less expensive) or engine compression brake (preferred).

wolfe10 wrote:

Nomadac wrote:
350HP ISC 8.3L engines have exhaust brakes and the 400HP ISL 8.9L use Jake Brakes.

Agree on C which will have exhaust brake.

The L was offered with EITHER exhaust (less expensive) or engine compression brake (preferred).

Yes the 400 HP ISL engine was equipped with a Jake two stage brake. I do not ever remember seeing any 400 HP ISL engines with an exhaust brake. I know that Travel Supreme MH's with the ISL engine all had Jake Brakes std.

But the poster said his unit is a 350 HP ISC therefore I believe he has an Exhaust brake, as Cummins never built a ISC with a Jake brake from my research.

If he found the serial # on his engine and called Cummins they could advise what the engine was built with.