Servicing

[focus-dave]

I apologise if this has been posted before, it probably has. I'm pretty confident/capable of servicing my car at home with the use of axle stands but the bit that puts me off is having to mess about bleeding the fuel system when I do the fuel filter, last time I serviced a diesel it had a priming button on the top and it couldn't have been easier but the 1.8tdci lynx lump hasn't got anything like that. Is it easy to do or is it a pain in the rear end. It's mot is due in march but so far struggling to get a wallet friendly price for a service (inc all filters) so gonna do it myself 

Cheers

[Tdci-Peter]

On 1/5/2018 at 3:41 PM, focus-dave said:

last time I serviced a diesel it had a priming button on the top and it couldn't have been easier but the 1.8tdci lynx lump hasn't got anything like that.

It is not just the 1.8, most Ford diesels are similar. The Transit and maybe Mondeo have permanent priming systems, but not, it seems, the Focus. However the 1.8 does seem to be harder than most.

There is no tank fuel pump. The main pump will not suck air. Any air on the inlet side will prevent starting. So it needs a priming bulb. The high pressure side is self priming, and is not a problem. I had massive problems the first time I did the fuel filter, but no problems next time when I did as below:

To be able to remove the bulb without letting a load of air in, I fitted a non-return valve before the filter. After changing the filter, I did not bother part filling the housing, but put it on empty. Then:

Partially release the filter outlet pipe (being very careful not to get any dirt whatsoever into the pump side of the filter), undo the filter air vent, and use the priming pump to fill the filter. Once only fuel & no air comes out of the filter outlet port, re-connect it, close the vent, and pump some more, quite hard. There must be no leaks from the filter. Then try starting.

Once it starts & runs ok (I got a little air in, so it stopped once, then re-started easily after I primed it some more), stop & remove the bulb. By holding the pipes pointing up until the last moment, you can refit the filter input connector without any air getting in.

The non-return valve I used was the 8mm version of: http://www.ebay.co.uk/itm/291512397207

By doing all the messy work before the filter, it greatly reduces the change of getting very expensive dirt into the pump or injectors! The priming bulb I had was not much good, without the non-return valve it would have been useless, but with it it just managed to do the job. The non-return valve was excellent, good seal backwards, and very little drop in the flow direction.

It has been in for over a year now, over 9000 miles, no side effects. If anything it makes starting more reliable.

This pic:

Shows the valve being fitted to the filter inlet pipe.

The pic below shows the valve in place, but with the priming inlet pipe pushed into the end.

 

Edited January 19, 2022 by Tdci-Peter
Update Photo

[Tdci-Peter]

48 minutes ago, focus-dave said:

Is it easy to do

I just found another pic, and a bit more info. I keep meaning to do a guide about this, but the old round tuit has not appeared yet!

The photo below shows the priming bulb. Not very clear, but the valve is at the bottom left, and the transparent hoses go from this inlet pipe to the filter inlet port via the bulb.

[Albert27]

I had a terrible job doing it on my 1.6 tdci; no matter how much pumping i did i just could not get it to start.  In the end, I had to resort to a tow start which forces the diesel through the lines.  But do as Peter has suggested first - the tow start is the last resort but it does do the trick!  The other option is do all the service yourself and then take the fuel filter to your local garage and ask them - they might be willing to just do that for you.

[iantt]

my primer broke today while i was doing a connect 1.6tdci, i normally prime like peters last photo basically primer is inline and air is forced back down the return pipe to tank. but as it broke on me i used a large syringe connected to the fuel return pipe and sucked the fuel though . was in the end easier than the primer pump

[FatHead1979]

I've found that once the filter is in place within the housing and FULLY topped up with diesel, I've not had any problems getting my car to start 1st time.  To help things along I tend to immediately rev and hold it to about 2000 RPM for approx 15 seconds.

What I can say is that if you try to start the car with any left in the filter, you're likely to have problems.  If you've not done one on the Lynx engine before I'd suggest buying a hand primer as a back up, at least if it doesn't start 1st time you've got the means to sort it out without having to run around desperately trying to buy a hand primer from where ever you can get to.

[stef123]

23 minutes ago, iantt said:

my primer broke today while i was doing a connect 1.6tdci, i normally prime like peters last photo basically primer is inline and air is forced back down the return pipe to tank. but as it broke on me i used a large syringe connected to the fuel return pipe and sucked the fuel though . was in the end easier than the primer pump

I bet you’ve had that primer since you were  a young lad too  

[FatHead1979]

5 minutes ago, stef123 said:

I bet you’ve had that primer since you were  a young lad too  

Nar....it'll have been passed down through the generations like a family heirloom 

[iantt]

Been in the family along time. Lol

[Tdci-Peter]

On 1/5/2018 at 7:05 PM, iantt said:

primer is inline and air is forced back down the return pipe to tank.

I found it takes quite a lot of pressure to ram fuel through the pump and into the return system. I am not surprised the primer broke!. Also there is a downhill bit from filter to pump, so you need to pump quite hard to get it through, and get the air out.

I was not sure at the time where the fuel and air was going, though I now suspect it was going out via the fuel pump return connection, from the intermediate pump stage, which I guess is where Ian was sucking fuel through from.  I doubt if it is possible to push air up into the high pressure parts of the system, having seen a diagram of a typical pump.

Overall, it seems that changing the fuel filter on a 1.8TDCI is really not a problem as long as you have some suitable equipment:

A bad primer plus a non-return valve. Or

A really good primer and ram it thorough. (Until it breaks!). Or

A good syringe to suck it through, or to top up the filter housing via the vent valve.

But like Damien says, it is essential to get almost all the air out before any attempt to start the car. And perhaps even more crucial to avoid getting any dirt into the line from filter to the pump.