BRUISER

Hey all,

Well the end of the KSB started leaking fuel a week ago.. so I contacted a local diesel shop and they gave me a new o ring for it.. I took "brace" bolt(17mm) out of end of KSB and put new o ring on it, put it back in and now no leaks Yippee.. but now KSB does not work?

FYI. I have my KSB wired to a switched.. I can flip switch and have power at the KSB but KSB is not activating.

so my question is does anyone have a diagram or a pic of what is inside the KSB and how it actually works? did something fall out when I took bolt out that I missed or did something get twisted inside , etc..

I plan to take it back apart tonight and get a mirror to look up inside but was hoping I could have some info with me when I try to fix this.

thanks

Alwaysworking

my ksb switch wont work untill the engine is somewhat warm.

BRUISER

oops I forgot to add my engine is a '92 CTD so KSB works when it is cold outside and then turns off when engine warms up..

what I need to find out is what is inside the KSB?

CaptainChrysler

http://www.scribd.com/doc/19099617/Bosch-Ve-Pumps

Try this. It is a basic overview of the VE. Nothing too in depth, but it might help.

BRUISER

thanks but nothing in there about the KSB internals

wannadiesel

Check ball and spring missing? Did you notice anything fall out when you pulled the solenoid?

jimbo486

that was my guess. i'm sure there's at least a spring inside there that eventually is overcome by case pressure at higher RPM's or 12v to actuate the motor and advance the timing.

Alec

I just replaced the same o-ring on my truck (I hadn't done it when I re-sealed the rest of the pump). The KSB works. Nothing fell out or tried to fall out.

When you put that pressure relief valve (as far as I can tell, that is what that "bolt" really is) in, I think it needs to seat and seal against an edge inside the KSB housing -- if you didn't tighten things up enough or if the sealing area on the end of the bolt were damaged, it might cause your problem.

Before you kill yourself, however, try powering & unpowering the solenoid with the engine OFF. You are supposed to be able to hear the solenoid "click" when voltage is applied to it. It is always possible that the solenoid decided to coincidentally burn out the same day you replaced the o-ring . . .

Sorry I don't have a good picture or diagram.

dillenger1

you may have dropped a shim in the cap when it was off.They have shims in both caps to increase the spring rate

BRUISER

thanks for info.. did not get to it last night.. but will be taking it apart tonight to look inside

BRUISER

well I pulled it out last night and there is nothing inside.. the bolt is a presure relief valve.. i put a mirror in front of it to look inside and nothing is inside.. so I am now thinking solenoid may have gone bad. I do have power going to solenoid and bolt seals with no leaks .. I guess i will replace solenoid next..
after that the next step is to repalce entire KSB unit

BearKiller

I did not know that the KSB had a "solenoid" as any part of it; I thought the terminal on the KSB went to a heat element that heats a wax pellet and the expansion of the wax is what operates the valve.


I know they work opposite on inter-cooled versus non-IC engines but I still get confused as to which works which way.


Many of the other BOSCH VE applications have a manual cable-operated KSB mechanism, much like a choke cable; I would love to find one of these.

Alec

The trucks with an after-cooler use a solenoid to close a by-pass passage in the KSB unit. The solenoid is controlled by a thermal switch in the intake manifold powered from the "ignition" wire at the shut-off solenoid on the pump. Between the switch and the solenoid is a resistor, mounted to a bracket on the side of the head, that reduces the voltage to the solenoid down to ~ 8V (when current is flowing through it & the solenoid -- if you just disconnect the wire at the solenoid you will get battery voltage). The solenoid operated KSB works instantly when you connect & disconnect the voltage to it -- when it is working you can hear the engine speed pick up and drop off connecting & disconnecting it.

The non after-cooled engines have a "wax motor" that opens the bypass passage in the KSB unit. As you said, there is a heating element to which voltage is applied when the "ignition" is on, and once it heats the wax up, the wax opens the bypass. I think that it, too, may have the voltage reducing resistor, but I am not sure. The wax motor style does not work instantly, but relies on the delay to approximate the time required for the truck to warm up.

BearKiller

Thank you.