Engine/Transmission (1994 - 1998) pac back

[JApplegate]

i want to install a Jacob's exhaust brake. i want to know what i have to do to the engine to install it and about how much this will cost and the exhaust brake. i have a manual and 93

 

[HoleshotHolset]

If you buy a new exhaust brake - expect to spend at least $800 or so.



You need to install 60-lb exhaust valve springs... or the brake won't work too well.



I would venture to guess that you're looking at about 4 hours or so of labor to do it all...



Matt

 

[JGheen]

Originally posted by HoleshotHolset





You need to install 60-lb exhaust valve springs... or the brake won't work too well.







Matt

Its not that they won't work too well, the stock springs will break if you don't install the heavier ones. The stock springs can't take that huge added exhaust backpressure that the exhaust brake produces to slow the engine down. Just an added explaination

 

[HoleshotHolset]

JGheen: "... the stock springs will break if you don't install the heavier ones. "



Where did you hear that from?



Matt

 

[JGheen]

From many people, why, have you never seen the stock springs break with use of an exhaust break?

 

[K5IP]

Jimmy,

I put a pac brake on my 95. Very easy to do, about two hour labor. My pac brake came with two oprions for braking pressure. You simply pick the vent size for the praking you want. Standard for the original springs, or the higher pressure (higher braking) if you are going to change the valve springs.

The problem, as I understand it is not springs breaking, but that valves can float (due to higher backpressure) and be damaged, thus the requirement for higher spring pressure.

I pull a 7500 lb 5th wheel and find the standard condition, (no spring change necessary) is great even in mountain west. In fact I might find the more agressive braking condition to be annoying.

have fun

Roger

 

[JGheen]

Yeah, I have heard of the valve float issue with brakes and stock springs, but in rare cases I have seen the springs break and cause damage due to prolonged use of stock springs with a E-brake.

 

[Coalsmoke]

Heard of floaters but never a broken one, but anything is possible I guess. Is there a way to tell if a person has 30lb stock or upgraded 60lb springs just by looking at them? I wouldn't mind finding out what my truck has (bought it used w/ brake).

 

[HoleshotHolset]

Coalsmoke: If it has a brake... I'd hate to think that it has OEM springs... most people upgrade both at once...



Matt

 

[BV]

Originally posted by Coalsmoke

Is there a way to tell if a person has 30lb stock or upgraded 60lb springs just by looking at them? I wouldn't mind finding out what my truck has (bought it used w/ brake).

The stock intake and exhaust springs looked identical on my 96. The heavier springs are different looking in size and shape. This may help you if the previous owner changed only the exhaust springs.

 

[JGheen]

Originally posted by Coalsmoke

Heard of floaters but never a broken one, but anything is possible I guess. Is there a way to tell if a person has 30lb stock or upgraded 60lb springs just by looking at them? I wouldn't mind finding out what my truck has (bought it used w/ brake).

I called my local Cummins place and they just told me to give them the engine serial ID # and they found that my cylinder head had the lower pressure springs installed at the factory. They also said that some 12v's had the heavier springs installed at the factory and some didn't.

 

[HoleshotHolset]

"They also said that some 12v's had the heavier springs installed at the factory and some didn't. "



I've never heard of that before...



Matt

 

[JGheen]

Originally posted by HoleshotHolset

"They also said that some 12v's had the heavier springs installed at the factory and some didn't. "



I've never heard of that before...



Matt

Damn, I guess I am getting fed some jacked up information from some of the guys at Cummins West in Bakersfield... .