I am looking at a truck, its a 1992 250, 92,000 miles 5 speed 3.55 limited slip. Truck looks really good, no rust, etc. It said 1 older owner, and very well maintained. With all the garage on it, i believe it was 1 owner. It has a Boost guage, Pyro, and a Tach.

It also has a Jake brake. are these good or bad for the engine?

 

Hasn't hurt my motor yet, and I bet I'll never have to change the brakes again.
AJ

 

What you refer to as a jake brake is actually an exhaust brake. The exhaust brake mounts on the backside of the turbo or downstream in the exhaust piping and uses a butterfly valve or gate controlled by a solenoid to actuate the valve or gate. A jake brake on the other hand is oil actuated and solenoid actuated to hold the exhaust valves open at compression.

You might want to check with the owner to make sure heavier 60lb exhaust valve springs were installed with the brake installation.

The exhaust brake has been tested and used for years and comes as a stock item on almost all medium duty trucks that run the ISB, B model, C7, MB engines.

 

If you tow you will love the exhaust brake. Like Monty said, make sure it has the 60# springs or the brake will float the valves.

 

Can the engine be damaged because of the valve floating?

 

yes engine damage will result ,valves hitting pistons kinda makes a mess