BC III jake break remove....

[Joe58]

Hi everyone, newbie jointed,
I bought a 2nd BC III Cummins STC400 from private yard, don't know how long it was laying around on the yard, it came out from truck engine installed Jake break boxer, i'd like remove Jake break and convert it to Marine, was install Heat exchange & exhaust water manifold.....if remove Jake break box on the top 3 cylinder, do I need to do some thing on the cylinder head or readjust valves, injectors...….need someone here help and give some ideal, thanks...
Joe

 

[RZucker]

You should be able to remove the Jake housings and replace the long Jake brake studs one at a time using the torque pattern in the service manual using the proper Cummins bolts for the rocker housings. You will also need to get plugs for the Jake brake oil feed holes in the rocker housing, I don't remember what the threads are on those plugs but Cummins will know.
The top covers should bolt right back on the rocker housings (may have to dig the dirt out of the bolt holes). Myself, I would run the overhead afterwards anyway.
Hope that helps.

 

[Truck Shop]

Before anything send us the CPL number on the engine plate {if it has one} located on left front accessory housing. {CPL=Controlled Parts List}. Because you listed the engine you have
as a BCIII Cummins STC 400 {Cummins never made a BCIII with STC injectors} You would have to have a New Big Cam IV to have STC injectors. Removing the jakes is the same for
both BCIII and IV engines. But adjusting the valves and injectors is different between the two engines. So send us the CPL so we know which engine you have} Please.

 

[Joe58]

Thanks for quick respond guys, Cummins new to me so I don't know much.
@Truck Shop, sorry double check it said NTC not STC, I searched on net it shows engine details, same serial number, but the CPL difference, the one on plate stamped CPL#743 or 745 because the last number nearly lost can't read clear

 

[Truck Shop]

Ok, CPL #743 is a BCIII, the 745 does not exist as a Cummins CPL number. exhaust is .014-intake .027, injector 5 inch lbs. Get your self a manual for procedure to set valves and injectors.
That engine was rebuilt by a aftermarket rebuilder more than likely with the etched plate Cummins are stamped. And was rebuilt using the #743 CLP {not uncommon}. Many rebuilders used
the #625 CPL for rebuilds as it was a very common CPL.

 

[Joe58]

@Truck Shop: Yesterday, I went to Cummins agent asking for the plugs Jake brake oil feed holes, they haven't got on stock then told me go to Cummins wreck yard, the guy there told me bring Jake break & rocker housings to him, he gave me 3 plugs and told me took off all the wider vales bridges, swapped for me narrow one, I haven't chance to ask him, because he was too busy......took rocker housing and vale bridges home gave him all the Jake housings....look on the workshop manual didn't say any about changing vale bridges...don't know why he told me changing them...…After installed adjusted vales & injectors, engine started and run good now "sound good compression"....but it's keeping leak oil where is power steering mounted...the power steering removed when I bought, then I cut the plate "5mm" thick use proper gasket & sealer bolt to lock it, but it still leaking from there.....is there any plug need to block it?
Best regards
Joe

 

[Truck Shop]

The narrow valve bridges are used when there are no jakes, he wanted the valve bridges that went with the jakes. As far as the oil leak at the oil pump where the power steering pump
was mounted the only thing I can think of is there was old gasket material still stuck on oil pump opening or the plate you used was not flat.

 

[Joe58]

The narrow valve bridges are used when there are no jakes, he wanted the valve bridges that went with the jakes. As far as the oil leak at the oil pump where the power steering pump
was mounted the only thing I can think of is there was old gasket material still stuck on oil pump opening or the plate you used was not flat.

Thanks mate, the surface was really clean straight, i swapped the original plate then cut thicker paper gasket and used master gasket silicone where is applied oil & heat, waiting for few hours for sealer intact, then start engine,it’s still leaking but a little better, the oil gauge jumped around 4.2 bar