Injector line nut size for Yanmar 2qm15?

[bony]

Hi,
To bleed the injector lines of my 2qm15I I need a particular sized spanner to undo the two injector line nuts at the top of the top injector pump at the front of the engine. I can't get a normal spanner on them as they are way too close together so I was thinking of modifying a ring spanner with a slot cut out of it big enough for the injector line to pass through.

Does anyone know what size spanner I need for these nuts?

Other 2qm15 owners must have had the same problem trying to get access to these nuts, particularly the inside one, so I wonder how they dealt with the problem?

bony

[Wotname]

Other 2QM15 owners probably bleed at the injector end of the line rather than at the pump end.

At least that is how I do it on the 2GM20 which is very very similar. Just crack the banjo bolt on the top of the injector.

However the nut you describe is 10 mm - I THINK!! And the spanner you want is a tube spanner.

If you don't get a definitive size before hand, I'll check tomorrow

[bony]

Thanks for the quick reply Wotname.

I agree that cracking the last injector should be enough but on my engine I don't seem to get a good result at that point without first bleeding the nuts on top of the injector pump, particularly that difficult inside one.

Cheers.

[Terra Nova]

Your tool kit should include a dial caliper--the plastic ones are OK--so you can measure this kind of stuff yourself.

[four winds]

Tube spanner is needed for sure. Also known as a brake line wrench. Would have been impossible to replace my lines last year without one. 3gm30f though.

I recall 10mm as well. However not 100% certain. I you can't verify this let me know. I'll dig down into my cockpit locker and put a wrench on a line and let you know.

[bony]

"Your tool kit should include a dial caliper--the plastic ones are OK--so you can measure this kind of stuff yourself."

Good advice Terranova, but I'm trying to determine the size now so I can get the right tool for the job before I make the trip down to the boat on the weekend.

Thanks for the reply four winds,

Thought I'd post an image below showing the two nuts causing the problem. As you can see there is very little space between them. They look bigger than 10 mm though.

[Wotname]

Originally Posted by bony

….. They look bigger than 10 mm though.

Yep, they are. Belay the 10 mm and try 17 mm
At least the ones on my 2GM20 are and the body on the injector pump they screw into is 19 mm. The other end at the injectors are also 17 mm but housing at there is only 17 mm.

[Terra Nova]

Originally Posted by bony

...Good advice Terranova, but I'm trying to determine the size now so I can get the right tool for the job before I make the trip down to the boat on the weekend...

If you had had the caliper in your tool kit, the last time you were on the boat, you'would know, precisely and with great certainty, what size tool(s) to get. There will be a next time. So, while you're shopping for tools...

[bony]

That's the info I needed, thanks Wotname.

I'll check out my local tool supplier for a 17mm tube spanner, (and a cheap set of Terranova's calipers).

Thankyou everyone the help and advice.

bony

[Terra Nova]

General Tools 6 in. 4-Way Dial Caliper-142 - The Home Depot

[GrahamHO]

Originally Posted by bony

Thanks for the quick reply Wotname.

I agree that cracking the last injector should be enough but on my engine I don't seem to get a good result at that point without first bleeding the nuts on top of the injector pump, particularly that difficult inside one.

Cheers.

Ditto to what Wotname advised. But if you want to loosen that nut, get an adjustable divider in there measure across the flats of the nut in question then go to a tool shop. It should be in millimetres. If a correct socket in 1/4" or 3/8" drive is too thick to fit in the space you can thin it down on a bench grinder.


I'm not sure why you need to bleed from that nut. There should be proper bleed screws. There are on the 2GM20 anyway.

[bailsout]

I have same engine and became very proficient in bleeding the lines on these. What boat do yo have? And what problem have you been having?

[DMBOS]

I would not loosen the lines at the injector pump end - bleed at the injector end of the lines. If you have some reason to do the pump end of the lines, you have to hold the lower flats with a 19mm wrench. You do not want to loosen the lower fitting as there is an o-ring seal between the injector pump and the lowering fitting, which is probably old, and possibly brittle, and could present a "high pressure" leak. And, if it loosens, it has to be torqued to 30 ft lbs (?). And if your seals leak afterwards, they have to be replaced ! And that is where you get the little bitty spec of crap in there - and it just gets bad ! Crack the 17mm nut at the injectors - if accomplishes the same thing

[Wotname]

Originally Posted by DMBOS

I would not loosen the lines at the injector pump end - bleed at the injector end of the lines. If you have some reason to do the pump end of the lines, you have to hold the lower flats with a 19mm wrench. You do not want to loosen the lower fitting as there is an o-ring seal between the injector pump and the lowering fitting, which is probably old, and possibly brittle, and could present a "high pressure" leak. And, if it loosens, it has to be torqued to 30 ft lbs (?). And if your seals leak afterwards, they have to be replaced ! And that is where you get the little bitty spec of crap in there - and it just gets bad ! Crack the 17mm nut at the injectors - if accomplishes the same thing

Exactly...


Plus
Repeat - crack the 17mm nut at the injectors, not at the pump!

[GordMay]

BLEEDING THE FUEL SYSTEM (Purging of air which causes shutdown)
This bulletin contains helpful information for bleeding the fuel system of a Yanmar Diesel and other small diesels as well. Please post where your field service personnel can review.
Since the presence of air in the fuel system anywhere between the fuel tank and the injector will "use a no start or erratic running condition, always bleed the air from the system when the fuel system is disassembled, filter changed or run out of fuel.

1. Make sure fuel tank off is in "on" position.

2. Bleed the air from fuel filter. Loosen the air bleed screw at the top of the fuel filter body and operate the manual handle the lift pump until the air bubbles completely expel in the fuel flowing from the filter.

3. Bleed the air from the fuel return pipe. Loosen the connector bolt of the fuel return pipe installed on the fuel injector, and bleed the air by operating the manual handle of the lift pump. (If there is more than one injector, bleed the one at the end of the line).

4. Bleeding the air from the fuel line - (line from the filter to the injector pump). Loosen the air venting screw at the injection pump and operate the manual handle of the lift pump until an the air bubbles are out.

5. Bleed the air from the fuel injector. Loosen the nipple on the fuel injector side, set the throttle to half and the decompression lever to the decompression position and crank engine. When no more bubbles appear in the fuel flowing from the end of the injection pipe, re-tighten the nipple.

➥ http://ldmarineservice.com/files/yanmar_bulletins.pdf