3CX JCB 1997 Maintenance questions

[doobin]

Change the lift pump for an electric inline one. No more hassle.

 

[V8Druid]

....The sedimentor needed a good scrub and I've replaced the fuel filter.
Now I'm trying (unsuccessfully) to bleed the fuel system. It seems the lift pump isn't delivering any fuel at all.
I'm missing the safety prop, so all this has to be been done with the shovel on the ground (not ideal).
The quickhitch seems to have a safety pin that blocks the grab and prevents an unintended dismount.

was it running before you did all this ?
is there a gauze filter in the bowl, blocked solid? or a tubular gauze filter in any banjo unions?

with the safety pin in, at least you won't have the bucket fall off ... any pix of the hitch ?

 

[V8Druid]

Change the lift pump for an electric inline one. No more hassle.

you do love your leccy lift pumps Ruben ....

 

[doobin]

you do love your leccy lift pumps Ruben ....

Yup, they just work. Mechanical lift pumps are 1900's technology. We're nearly 20 years into the next century...

 

[V8Druid]

Yup, they just work. Mechanical lift pumps are 1900's technology. We're nearly 20 years into the next century...

..... much like the millions of mechanical pumps that have put in decades of service before needing attention for over a century

 

[doobin]

..... much like the millions of mechanical pumps that have put in decades of service before needing attention for over a century

Well it’s not working for him now is it?

 

[Rob65]

I’ve had a lift pump not work when operating the hand leaver when the cam in the engine was in the wrong position.

Have you tried turning the engine a bit and then operating the lift pump leaver again?

Rob

 

[V8Druid]

I’ve had a lift pump not work when operating the hand leaver when the cam in the engine was in the wrong position.

Have you tried turning the engine a bit and then operating the lift pump leaver again?

Rob

most common 'fault' / oversight with a cam driven mechanical

Well it’s not working for him now is it?

unknown Ruben .... may be pumping its heart out against a blocked gauze ..... or as above

 

[Gecko]

Change the lift pump for an electric inline one. No more hassle.

I'm starting to give that serious consideration

was it running before you did all this ?
is there a gauze filter in the bowl, blocked solid? or a tubular gauze filter in any banjo unions?

Yep - was running well.
No gauze in the sedimantor that I can see.
The only banjo fitting I can see is on the filter housing - are there any upstream?
The sedimentor had 1/4" deposits and I drained the filter into a clean tin - what came out was nasty. So a restriction/blockage would not be a surprise.

I removed a blanking plug from the sedimentor to make sure there was no back pressure* and I've 'keyed' it a couple of times to rotate the cam, but no change in feel.
I'll remove the outlet line and check for flow.

Edit: Have I misunderstood the plumbing?
I assumed the lift pump draws directly from the tank, but the hose layout suggests the lift pump draws through the sedimentor.


Edit:
* Don't do this - opening a port on the sedementor will guarantee you'll never prime the system.

... any pix of the hitch ?

Sure (shown with obligatory Eucalypt for Routy56!)

 

[Gecko]

Have I misunderstood the plumbing?
I assumed the lift pump draws directly from the tank, but the hose layout suggests the lift pump draws through the sedimentor.

Ok, I'm getting closer to the truth.
The sequence seems to be: Tank - sedementor - lift pump - spin-on filter - HP pump.

The reason it takes ages to prime is that you are sucking air through half the system before the lift pump sees any liquid.
I'm now going shopping for a sedimentor seal. The one I have is a bit crusty and I have no plans to repeat this process any time soon.

 

[diggerjones]

Check the filter under the banjo feed bolt on top of fuel pump. If it has one

 

[CPS]

Sediment bowl is your culprit..... seals need replaced every time you open it as diesel makes them swell. Also you can strip down the lift pump and there is a gauze inside it which may have dirt in it to.

Perkins can be the worst to bleed after airlock s in my opinion but just make sure everything is airtight and it will go.

 

[V8Druid]

Sediment bowl is your culprit..... seals need replaced every time you open it as diesel makes them swell. Also you can strip down the lift pump and there is a gauze inside it which may have dirt in it to.

Perkins can be the worst to bleed after airlock s in my opinion but just make sure everything is airtight and it will go.

aye ..... and usually need cracking off at the injectors too and cranking to bleed... lil' bar stewards to start after getting air in 'em

gauze is a disc above/between the bowl, inside the pump and only evident when you go looking for it

 

[Gecko]

Annnnnd we are running again!

Sediment bowl is your culprit.....

I couldn't get the correct seal locally, so settled for an O-ring. Not ideal, but better than the old one!
Understanding that the sedementor has fuel sucked through it helped a lot.
I loosened the outlet from the lift pump and pumped away until the sedementor was full and liquid arrived at the pump.
Tightened the union and kept pumpiing until fuel flowed from the bango on the filter housing.
Loosened the unions on a couple of injectors, but couldn't get fuel to flow.
Tried the key and it's all good.

Check the filter under the banjo feed bolt on top of fuel pump. If it has one

I haven't seen anyone listing the same lift pump I have. It doesn't have a removable top, but rather a large (1") brass nut on the input port. I assume there would be gause behind that.

Today I have the joy of rebuilding a couple of cylinders.

 

[diggerjones]

Annnnnd we are running again!


I couldn't get the correct seal locally, so settled for an O-ring. Not ideal, but better than the old one!
Understanding that the sedementor has fuel sucked through it helped a lot.
I loosened the outlet from the lift pump and pumped away until the sedementor was full and liquid arrived at the pump.
Tightened the union and kept pumpiing until fuel flowed from the bango on the filter housing.
Loosened the unions on a couple of injectors, but couldn't get fuel to flow.
Tried the key and it's all good.


I haven't seen anyone listing the same lift pump I have. It doesn't have a removable top, but rather a large (1") brass nut on the input port. I assume there would be gause behind that.

Today I have the joy of rebuilding a couple of cylinders.

The fuel pump not the lift pump

 

[Gecko]

The fuel pump not the lift pump

Ah sorry - wrong pump. No banjos on that pump either.

Q. What is the difference between a banjo and a trampoline?

A. You have to take your shoes off to jump on a trampoline!


I think I found the leak

 

[V8Druid]

I think I found the leak
View attachment 9143

yeh that might cause it

 

[Gecko]

Took the old boy to do a bit of work today (first time I've driven a backhoe, so I'm without a reference).
The driveway had developed a center hump, so I thought it'd be an easy job to shave the top off.
It started well enough, but started to feel like the engine was loosing power.
After playing around, I worked out what is happening. What ever height I set the shovel, it slowly drops about 3" and is then stable.
Does that sound like leaky rams or control valves?
(the hydraulic fluid is getting low - how low can it get before it sucks air?)

 

[craig]

Has your machine got boom suspension? srs I think jcb call it, if fitted and turned off, it could be the control solenoid leaking.

 

[doobin]

Ah sorry - wrong pump. No banjos on that pump either.

Q. What is the difference between a banjo and a trampoline?

A. You have to take your shoes off to jump on a trampoline!

Ya gotta purdey mouth, but yer on the wrong side of bumfuck boy...