2h fuel bleed screw leaks

[cruiser86]

Been chasing air in the fuel system for quite some time. Today I installed a new (original) bleed nipple since I noticed the old one was sweating a bit. With the new bleed nipple it leaks even more. Unfortunately part number 23319-48010 is no longer available. Are there tricks to seal the bleed nipple? Loctite or simulor? Or even better, is there someone in Europe who has a spare one that he is willing to sell?
Maybe @WRNG Lifestyle has one kicking about?

 

[duncanrm]

Are you using two new copper crush washers for the bleed bolt.. are you sure its coming from the nipple itself? Sounds like the seat the valve sits against is compromised if you are confident (it seems unlikely, but possible). No loctite etc should be required.

If nothing else you could run without a bleed bolt if you can find a matching banjo bolt like the non bleed side of the filter (inlet) - the pump itself has a bleed point as well.

Any good diesel shop should be able to sort out a banjo bolt for this application

Every time those banjos are disturbed I replace the crush washers either side of them.

 

[duncanrm]

For a sucking air fault on a 2H.. here's my complete list of things to consider:

2H - Sucking Air/Fuel Restriction

docs.google.com

 

[cruiser86]

For a sucking air fault on a 2H.. here's my complete list of things to consider:

2H - Sucking Air/Fuel Restriction

docs.google.com

Followed this one earlier replaced all washers with own from Amayama. It is def coming from the bleed nipple. Fixed it for now with Loctite 55. Thanks for the input, much appreciated.

 

[sodafeld1]

I reckon you may have some crud or a tiny bur. The bleed nipple is the same as the brake nipples. With the cone shape at the end and fine thread, it is designed not to require any goop. Using goop defeats the purpose every time you bleed it by putting crud in there. I would give both female and male surface a bit of burgundy coloured scotchbrite, flush with diesel and retry next fuel filter change, personally. Unless your female thread is knackered from over tightening. Like the fuel line olive ends they just need a firm nick for tightening not high torque.
Diesel mechanics should be clean.

The design is good and allows you to bleed anytime, anywhere without goop, which can happen indeed.

 

[cruiser86]

Will try to clean the inside of the banjo bolt where the bleed nipple seats. Today when I wanted to leave work same problems as before; air in the system. I couldn’t get the air out with the primer pump, same as previous times (every time it has been quite troublesome to get diesel back at the bleed nipple). Since last time, I have a cheap 24v fuel pump installed, but not hooked up permanently. I quickly plumbed it in and I was able to bleed the system. I had to open the nipple quite far and heard a mechanical “plop” when the fuel started to flow. Can there be something simple wrong with the feed pump?

So far I have done/replaced the following:
- new original fuel tank (old pick-up)
- new flexible fuel lines
- removed sedimeter to eliminate
- new original crush washers
- new fuel filter
- replaced aft hardline which had a kink in it

Thanks and appreciate any input

Picture of the cheap electric pump installed the background

 

[dmjay]

While you're at it, the bleeder should be on the outlet side of the fuel filter housing. It was a mistake from the factory it seems.

 

[duncanrm]

I'd definitely be looking at your lift pump based on your description at this point.. two things of interest:

• A video I made of one that was causing problems for me:
• Details of the tebuild kit for the pumps: New photo · Wednesday, Jun 19, 2024 ð¸ - https://photos.app.goo.gl/CFuE9x1TiGWTpBQJ7

An entire replacement lift pump is not terribly expensive (at least in Australia, $AUD250 or so).. unsure of options for you in Europe.

Dont forget to replace crush washers again when reinstalling, and check out that little gauze filter screen on the inlet to the lift pump at the same time.

 

[sodafeld1]

The bosch manual bleeder pumps are a definite upgrade, don't have to unscrew to pump.

A fuel leak is often deceptive from where they actually start unless you have intimate knowledge of the engine. What has been done, by whom, when and how. Sounds like you are going through the circuit which is all you can do. Getting the engine bay super clean can help.

I really like copper crush washers over aluminium if I can use them for the application. Before installing or reinstalling I heat them up with a torch, glowing red, then let it cool down. It anneals them and makes the copper soft again.

Flexible fuel lines can get abraded or tear depending on the rubber. One time I used a softish viton flex line from the sedimentor to the ip. It had to sharp a kink and teared at the bend from the sharp bend at the union to the hard line and vibrations. I knew exactly where it would be as I installed it.

Every join, union, connection is a possible opportunity for a leak.

Folks here often advise a clear flex line to the ip to determine if the leak is before the pump.

How long have you had your vehicle? Have to spend time with it. Once diesel is going well it is set and forget.

 

[cruiser86]

Thanks everybody for the input.

@duncanrm , I have seen the video & was wondering if the cam follower could let air pass trough into the block and if it could get stuck-ish and prevent the bleeder from working.
A new one must arrive from Japan, i could ask locally to see if anybody has a spare but not the biggest fan of troubleshooting a problem by adding unknown condition parts. It will probably be around $AUD 550 before it is on my doorstep.

@sodafeld1 , i'm fairly new to the vehicle (and diesels in general). I have it for a year and a half but only used it for a couple of months (with months in between) due to the road tax being crazy ($AUD 592 per month in Australian units € 335,- local) . It will be tax exempt in december next year though, 40 years old

Will keep digging and monitoring. The problem is on and off and seams to appear only on start up at the moment. This lead me to rule out the feed pump but maybe I need to revisit that idea. My biggest issue is that it is difficult to replicate the issue which prevents me working on it when it suits me

 

[duncanrm]

T

@duncanrm , I have seen the video & was wondering if the cam follower could let air pass trough into the block and if it could get stuck-ish and prevent the bleeder from working.
A new one must arrive from Japan, i could ask locally to see if anybody has a spare but not the biggest fan of troubleshooting a problem by adding unknown condition parts. It will probably be around $AUD 550 before it is on my doorstep.

I havent seen one fail in a manner that results in air past the cam follower.. that'd also presumably result in diesel into oil. But any fuel flow restriction is quite difficult to tell apart from a "sucking air" issue. The lift pump is not Toyota specific and is fitted to other vehicles - I wish I had a few part numbers or a vehicle list that matches but I dont.

 

[cruiser86]

Was stranded at work yesterday. Made it 500 meters to the nearest garage.
Couldn't get (presumably) the system bled. It kept dragging air in I suppose or it is not able to let fuel pass.
Replaced one of the 3 month old flexible hoses on the spot. Wasn't looking the best

After replacing this i was able to get the system bled en running again and made it home just fine.
Even though this hose didn't look great I have the feeling this wasn't the culprit. I think it is the primer pump or the lift pump itself.
This because there was sometimes no flow to the bleed screw when working both the manual primer pump and having the electric pump running.
Will dive into the schedule of the lift pump to see what can fail there en possible restrict flow or lets air in. Same for the primer pump.

NB, primer pump is already replaced by a Bosch unit.

 

[sodafeld1]

was that an actual fuel hose? hoses aint hoses, rubber is not nitrile or viton, fuel hose is different to air or vacuum etc..some expand some contract.
If that hose was fresh, it does not look fuel resistant, also it looks to be contracting inwards which too would restrict fuel..

If a diesel engine is spick and span with no leaks, there is no wet spots in the bay. Ideal is dry.

 

[cruiser86]

was that an actual fuel hose? hoses aint hoses, rubber is not nitrile or viton, fuel hose is different to air or vacuum etc..some expand some contract.
If that hose was fresh, it does not look fuel resistant, also it looks to be contracting inwards which too would restrict fuel..

If a diesel engine is spick and span with no leaks, there is no wet spots in the bay. Ideal is dry.

That was indeed a special fuel hose. Pulled the data from the online order. It states specifically that it is rated for diesel fuel oil.

Engine and engine bay is dry on the fuel side.

 

[sodafeld1]

Wonder what made it crack like that? Oh sorry that was the old hose..