Jake Brake Problems Also

[QCDriver]

I can not locate any of the electrical components, ground and solenoid. The brake works very erratic I think it's probably a ground problem. I've traced back from both heads to a main harness that drops out of site at rear of engine. Looking for some help before I start cutting factory loom apart. When it works it's strong which leads me to electrical. Oil psi good also.

I have a '01 E-Tech.

Any and all help is appreciated.

Thanks

[rhasler]

The engine brake solenoids are located under the valve covers. They sometimes quit working properly. Did this just crop up or have they been acting erratically since new? There is an update kit available through Mack Partswhich corrects some weak brake and other problems associated with your model Jake Brake. I will look for the service bulletin later and let you know

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[QCDriver]

Problem has happened before but only on damp days. According to Jacobs there is some kinda soleniod relay some where, along with, some weather pack 2-way connectors.

[rhasler]

On your engine the engine brake is supplied power through the engine ecu. There is a disable relay for the ABS system but that doesn't sound like the probelm. I would look at the solenoids personally, especially if nothing has been done with the Jakes/valve adjustment lately. If you haven't done anything with the Jake you may want to install the Jake overhaul kit. Jake suggests the brake be rebuilt at 150,000 miles. The overhaul kit p# 4559-31180 updates the Jake to current revision level and includes reset screws, springs, control valves, most of the snap rings, and solenoid o-rings. The exhaust valve yoke adjusting screws need to be checked for wear. If the screws measure less than .960" inches they ALL need to be replaced with current part number 421GC41CM. Installing the overhaul kit requires a slave lash setting change from .015" to .021". Most of these changes were implemented to prevent breaking of the valve yoke guide pins and subsequent valve dropping issues.

Edited June 10, 2010 by rhasler

[rhasler]

Here is an excerpt from SB 266-017:

For engine serial Nos. 0V0114 through 2R2728 (build date range November 14, 2000 through September 25, 2002), inspect the reset screw for the presence of 032053A stamped next to the screwdriver slot. If the screws are part No. 032053A, the brake has the 215SB321 kit parts. If the reset screws are any other part number, install kit part No. 215SB321, following all the instructions outlined in bulletin SB213027

Kit 215SB321 may no longer be available, but the parts are in the engine brake overhaul kit 4559-31180. You have to remove the engine brakes from the engine in order to install the kit which means the valves and engine brake settings must be adjusted afterwards. While this is done the valve yokes need to be adjusted and the exhaust screws checked for wear by measuring from the face of the hex used for adjusting the screw to the contact surface (part that contacts the valve stem). The measurment needs to be at least .960", if not replace the screws

[QCDriver]

Thanks for the info. I'm headed to Mack in the hour with these part #'s.

Thanks again.

[QCDriver]

Here is an excerpt from SB 266-017:

For engine serial Nos. 0V0114 through 2R2728 (build date range November 14, 2000 through September 25, 2002), inspect the reset screw for the presence of 032053A stamped next to the screwdriver slot. If the screws are part No. 032053A, the brake has the 215SB321 kit parts. If the reset screws are any other part number, install kit part No. 215SB321, following all the instructions outlined in bulletin SB213027

Kit 215SB321 may no longer be available, but the parts are in the engine brake overhaul kit 4559-31180. You have to remove the engine brakes from the engine in order to install the kit which means the valves and engine brake settings must be adjusted afterwards. While this is done the valve yokes need to be adjusted and the exhaust screws checked for wear by measuring from the face of the hex used for adjusting the screw to the contact surface (part that contacts the valve stem). The measurment needs to be at least .960", if not replace the screws

I was at Mack Baltimore, that kit is $450, kinda high if it recommended every 150k. Also I have that SB 266-017 and have not seen part# 4559-31180. I'm going to try and get parts elsewhere.

Can you tell when my engine was built?(1m1aa13y91w139664) My number on valve cover in unreadale. Do I have a 690,690a,or 690b? This is driving me nuts.

Thanks for your help.

[rhasler]

I was at Mack Baltimore, that kit is $450, kinda high if it recommended every 150k. Also I have that SB 266-017 and have not seen part# 4559-31180. I'm going to try and get parts elsewhere.

Can you tell when my engine was built?(1m1aa13y91w139664) My number on valve cover in unreadale. Do I have a 690,690a,or 690b? This is driving me nuts.

Thanks for your help.

The certification year for your engine (if original) is 2001. The original engine serial number is 1A0831. The 4559-31180 is listed in the bulletin under tune up kits. It covers all three versions of the brake assembly. That price does seem high, but its been awhile since I priced one.