Ben’s 2004 HZJ105 STD Spec 1HZ Manual

[Ben Stratford]

In preparation for our trip to Scotland next week, fitted a pair of new Bosch batteries:

Changed oil and filter. Changed gearbox and transfer box oil and next is the diff oils.
While looking at the fuel filter I noticed a non return valve installed:

Is the NRV the right way round though ??

 

[Ben Stratford]

Took the NRV off to test it and yes it is oriented correctly which is obvious now!
It is a small restriction in the line though reducing internal diameter from about 8.5 to 5mm. Is the valve necessary??

 

[frank rabbets]

The lift "pump" in the injector pump is fed by atmospheric pressure, (it sucks), roughly 14 psi which would force diesel up to 40 ft? so I guess a NRV would only be necessary to avoid fuel draining back to the tank in the event of an air leak. Nothing to lose by keeping it in. With the LC standing vertically on it's back there is plenty of Atmospheric pressure to supply the pump.

 

[Grimbo]

I reckon the NRV was fitted to overcome the common issue of the primer on top of the filter allowing air in and letting fuel drain back when engine stopped....
Personal opinion but I would junk the little jubilee clips and put some fuel line clamps in their place..... yours look fine but I've seen them allow air in because they don't fully clamp round their full circumference .....

 

[Ben Stratford]

Thanks @frank rabbets and @Grimbo What I’m finding is under any throttle fuel pressure is fine but at low revs steady throttle in any gear a sort of kangarooing as if there is fuel starvation. If I pump the primer before setting off this disappears but the primer which goes solid is then slack a few minutes later. The jubilee clips were a bit loose and I was wondering if there was air getting in. Can the primer button fail and let air in too? There’s some corrosion around the button?

 

[Grimbo]

Thanks @frank rabbets and @Grimbo What I’m finding is under any throttle fuel pressure is fine but at low revs steady throttle in any gear a sort of kangarooing as if there is fuel starvation. If I pump the primer before setting off this disappears but the primer which goes solid is then slack a few minutes later. The jubilee clips were a bit loose and I was wondering if there was air getting in. Can the primer button fail and let air in too? There’s some corrosion around the button?

Yes that's the normal thing that fails on the filter head letting air in ( the button )
Is this a new syndrome ? The 1HD FT's from the factory would give a similar symptom ...mine only did it at light throttle on a slightly uphill straight piece of road with a 40mph speed limit... you could feel it "surging" slightly in 4th or 5th gear ...give it more throttle and get over 2000 rpm it it would pull away .... the boost compensator tweak sorted it ....
When you get a bit of time just run a supply to the FIP from a clean can bypassing the filter and therefore also the fuel lines and if it runs well then work back from there .

 

[Ben Stratford]

Yes giving more throttle immediately gets past the surging. Pumping the button before a journey also gets rid of it but if left for a couple of weeks the surging starts to creep back in.
Thanks very much @Grimbo you have confirmed my suspicions. A new button / housing top has been ordered. If all ok will then remove the non return valve and see if it then remains primed properly at all times.

 

[frank rabbets]

The non return valve requires "power" to open it. If the spring inside is too strong it may not be letting enough fuel through.

 

[Ben Stratford]

Thanks @frank rabbets that’s handy to know. I have a bypass pipe and new clips with me. Got to Lockerbie today no problems at all.
When the new filter cap / button assembly arrives I will remove the NRV and see how it goes.

 

[Ben Stratford]

Ok, back from Scotland now and the new fuel filter housing has arrived ready to fit.
But had a new issue with brakes. Had sporadic normal pedal with occasional foot to floor moments and sporadic wheel juddering. Just 50 miles from home the low fluid light came in and 1 mile from home there was a grind of metal pad on to disc.
So the brakes must have been partly engaged I think.
What are the symptoms of a worn out master cylinder?

 

[felix2566]

Could be the master, and or sticky caliper,
If it was the master, would you not get all brakes being affected equally?
Has only one brake worn through the pad?

 

[Ben Stratford]

All 4 front pads were worn down to the metal having passed a not 2000 miles ago so I’m thinking it’s the master. All 4 pistons freely returned to normal position when the new pads went in. So a new Master has been ordered. Import duty on this one no doubt!!

 

[Grimbo]

All 4 front pads were worn down to the metal having passed a not 2000 miles ago so I’m thinking it’s the master. All 4 pistons freely returned to normal position when the new pads went in. So a new Master has been ordered. Import duty on this one no doubt!!

But if it's the master cylinder wouldn't it wear the rear pads too ?
What are the flexible brake lines like ? particularly the one from chassis to front axle ....I've known them to collapse internally and so hold pressure in the calliper's..... this single line would only affect the front brakes and the rears would not be holding on.... also this line would affect both front calliper's equally hence all four pads worn .
Pedal too the floor moments could have been the heat from the pads just boiling the brake fluid and causing brake fade and if the fluid isn't new any H2o absorbed into the fluid to boil and become vapour.... hence long brake pedal .