thanks for the video, helped me out, my pd130 was dripped fuel, i was doing 12l/100km, after changed the houses o-rings and gasket, i am getting 4.5l/100km. i also changed the vacuum pumps side o-rings because i had the full gasket & o-ring set
Thanks for the reply, just done mine same as you (so didn’t touch the fuel pump) can I ask how stiff should it be to turn the shaft, I need a pair of pliers to turn it, I was worried so I took it apart again but it’s all fine, however as soon as I tighten up the four bolts on the vacuum section it gets quite stiff?
Hi there, How would you diagnose the difference between a tandem pump failure and injector seal failure? Before I dive into the injectors I was hoping to rule out less invasive potential causes to my hard starting in the morning in the mornings. No diesel in oil. Cheers, Chris
Unfortunately lately there's no easy way to tell which is giving you poor start, does it smoke on startup? That would indicate fuel leaking past the seals into the bores. If there is no obvious sign, I would start with the tandem pump as its the easier and cheaper of the 2 repairs, if that doesn't fix it then it's going to be the injector seals
@@RJW_Customs There’s no smoke on normal start up, but on first start of day there’s a tiny bit of black smoke from what I assume is unburnt diesel. Clears in seconds then no smoke at all. I’ve changed fuel filter so assume that and the low pressure side is ok. Lifter pump in tank makes a gurgle sound when it primes.
Generally all pds have a little black puff of smoke on startup. This could be a sign of worn seals as it's got excessive diesel sat in the bores from leaking past the seals. But I would still start with tandem pump without solid proof on the injector seals. The lift pump is it just a little noise or a gargle like it's filling a cavity that's got air in it?
Thanks for the video. A person told me, I have to leak test a used or rebuild pump before use, how is that done? My pump seems to only leak (at least leaks through the orange seal). I don't know if I should just do what you do without the extra sealing and hope for the best, or buy new or used.
I've never leak tested one so i can't advise on this. If you've got fuel leaking into your oil then it's going to need the extra seals doing. If it's just leaking oil or diesel externally then you will be able to do the same as I did
@@RJW_Customs Thanks. Yeah the main culprit is not going through inspection cause of oil leak, I know this and the oil filling tube seal/(s) is bad, so both needs attention. But some say it leaks again after changing gasket, so they end up buying new. Is what you used on top a gasket maker?
@@RJW_Customs Cool. What did you do after assembling on the car. Did you turn on off ignition many times, or did you just start it? Wont there be some air and hard to start?
I can smell diesel of my tantrum pump and when I turn the heating on in the car? Can it be that the seals need changeing as I have my mk4 for 15 years now 😮
Handy video thanks! I’ve just got a diesel caddy that has supposedly got high oil pressure and diesel mixing with the oil I’ve narrowed it down to the tandem pump (hopefully) Would the full seal kit fix this or is it a case of a replacement?
Potentially but if its got high oil pressure it could be high enough to push past the seals, so I would check the oil pressure first, if it is high address that problem first and then look at the tandem pump. If it's not high then a full seal kit should sort it but you will have to replace the little seal that I left alone on this one
Thanks for the reply. Ah ok! My assumption was the leaky seal would be forcing high pressure fuel into the oil making the pressure go up? What else could be causing the high oil pressure? And what would be a symptom of high pressure so I can know when it doesn’t have high pressure 😅 Thanks
I dont think there is from memory. I would guess that maybe your injector seals are letting the fuel in the gallery in the head leak by and so it has to rebuild pressure up each time you go to start
OK, without seeing the vehicle and knowing all the history I'm purely guessing. But back to your original question I'm pretty sure there's not a one way valve in the pump
You will need to make sure you run the lift pump in the tank several times to fill all the gallery up with fuel and push any air out. Either activate it with a scan tool. Or cycle the key on and off multiple times letting it prime the pump
@@robbiewingate i cant tell if its from the vacuum pump or diesel pump because they're both one unit, i can just see lots of grit and diesel smell, now i know my valve cover isn't 100% sealing but it wouldn't make a diesel smell.. or is my oil diluted with diesel.. maybe inside the pump ? got a gasket set with new bolts ready.
@@RJW_Customs yes thanks, I mean if there is diesel flowing behind the first plate or if it should only be inside the part with the springs? ( that you didn’t open in the video) I assume the axle seals that is included in the kit is also changed by open this “inner pump”
Great video will be using this when I do mine tomorrow thanks for being so informative with the instruction
thanks for the video, helped me out, my pd130 was dripped fuel, i was doing 12l/100km, after changed the houses o-rings and gasket, i am getting 4.5l/100km. i also changed the vacuum pumps side o-rings because i had the full gasket & o-ring set
Very useful video, did you put silicone on the block side of the pump as well ?
Hi yes I did
Thanks for the reply, just done mine same as you (so didn’t touch the fuel pump) can I ask how stiff should it be to turn the shaft, I need a pair of pliers to turn it, I was worried so I took it apart again but it’s all fine, however as soon as I tighten up the four bolts on the vacuum section it gets quite stiff?
Hi there,
How would you diagnose the difference between a tandem pump failure and injector seal failure?
Before I dive into the injectors I was hoping to rule out less invasive potential causes to my hard starting in the morning in the mornings.
No diesel in oil.
Cheers,
Chris
Unfortunately lately there's no easy way to tell which is giving you poor start, does it smoke on startup? That would indicate fuel leaking past the seals into the bores. If there is no obvious sign, I would start with the tandem pump as its the easier and cheaper of the 2 repairs, if that doesn't fix it then it's going to be the injector seals
@@RJW_Customs There’s no smoke on normal start up, but on first start of day there’s a tiny bit of black smoke from what I assume is unburnt diesel. Clears in seconds then no smoke at all. I’ve changed fuel filter so assume that and the low pressure side is ok. Lifter pump in tank makes a gurgle sound when it primes.
Generally all pds have a little black puff of smoke on startup. This could be a sign of worn seals as it's got excessive diesel sat in the bores from leaking past the seals. But I would still start with tandem pump without solid proof on the injector seals. The lift pump is it just a little noise or a gargle like it's filling a cavity that's got air in it?
Yes. It sounds like a squirty gurgle. Like when a water pump first primes. Different sounding to other lifter pumps on other vehicles we’ve had.
Please, can you adjust the fuel check valve backpressure by rotating the screw? Thank you
Unfortunately I've never played with it so wouldn't like to say
Could you offer diesel leaking into the oil. Just had major work done. Same problem returned
Yes you could get diesel leaking into the oil via the little oil seal in the diesel pump aide which I didn't change in this video
Thanks for the video. A person told me, I have to leak test a used or rebuild pump before use, how is that done? My pump seems to only leak (at least leaks through the orange seal). I don't know if I should just do what you do without the extra sealing and hope for the best, or buy new or used.
I've never leak tested one so i can't advise on this. If you've got fuel leaking into your oil then it's going to need the extra seals doing. If it's just leaking oil or diesel externally then you will be able to do the same as I did
@@RJW_Customs Thanks. Yeah the main culprit is not going through inspection cause of oil leak, I know this and the oil filling tube seal/(s) is bad, so both needs attention. But some say it leaks again after changing gasket, so they end up buying new. Is what you used on top a gasket maker?
I used rtv which is labeled up as a gasket maker yes
@@RJW_Customs Cool. What did you do after assembling on the car. Did you turn on off ignition many times, or did you just start it? Wont there be some air and hard to start?
I can smell diesel of my tantrum pump and when I turn the heating on in the car? Can it be that the seals need changeing as I have my mk4 for 15 years now 😮
Handy video thanks!
I’ve just got a diesel caddy that has supposedly got high oil pressure and diesel mixing with the oil
I’ve narrowed it down to the tandem pump (hopefully)
Would the full seal kit fix this or is it a case of a replacement?
Potentially but if its got high oil pressure it could be high enough to push past the seals, so I would check the oil pressure first, if it is high address that problem first and then look at the tandem pump. If it's not high then a full seal kit should sort it but you will have to replace the little seal that I left alone on this one
Thanks for the reply.
Ah ok! My assumption was the leaky seal would be forcing high pressure fuel into the oil making the pressure go up?
What else could be causing the high oil pressure? And what would be a symptom of high pressure so I can know when it doesn’t have high pressure 😅
Thanks
Its possible but is the oil in the diesel or diesel in the engine oil? Best thing you can do is check the oil pressure with an oil pressure gauge kit
Is there a non return valve in the tandem pump im loosing fuel pressure and hard to start but once started runs fine
I dont think there is from memory. I would guess that maybe your injector seals are letting the fuel in the gallery in the head leak by and so it has to rebuild pressure up each time you go to start
I have replaced all the seals and still having this issue, the oil level isn't rising and I've done 500 miles since replacing the seals
OK, without seeing the vehicle and knowing all the history I'm purely guessing. But back to your original question I'm pretty sure there's not a one way valve in the pump
Okay thanks I try adding a nrv I the lines tomorrow and see how I get on
Any issues starting the van after due to disconnecting the fuel lines?
You will need to make sure you run the lift pump in the tank several times to fill all the gallery up with fuel and push any air out. Either activate it with a scan tool. Or cycle the key on and off multiple times letting it prime the pump
@RJW_Customs sound, thanks mate, did you put gasket sealant on every face or just the o ring?
can i put a dab of silicone on fuel pump gasket too ? im leaking some diesel from the pump area
Where it bolts to the vacuum pump? If only using a small smear so that none gets pushed into the pump when bolted up you should be ok
@@robbiewingate i cant tell if its from the vacuum pump or diesel pump because they're both one unit, i can just see lots of grit and diesel smell, now i know my valve cover isn't 100% sealing but it wouldn't make a diesel smell.. or is my oil diluted with diesel.. maybe inside the pump ? got a gasket set with new bolts ready.
Potentially either of those but if diesel is getting into your oil the tandem pump needs rebuilding anyway
Is it supposed to be diesel behind the first cover? Or do i have a bigger problem than bad gasket
It's made up of 2 separate pumps essentially so yeah first one is a diesel pump, the second one (closest to the engine) is a vacuum pump
@@RJW_Customs yes thanks, I mean if there is diesel flowing behind the first plate or if it should only be inside the part with the springs?
( that you didn’t open in the video)
I assume the axle seals that is included in the kit is also changed by open this “inner pump”
That whole part will be full of diesel
Thanks I will take a look when I take it apart, can’t find any photos online in that area
Hi mate can the tandem pump affect oil in fuel tank and can this cause car to shake at idle thanks
Yeah this can be the cause of getting engine oil in your fuel tank
@@RJW_Customs thanks when oil mixers with fuel can this cause a vibration at idle with out any codes
@Abdul Beany I've never had this specific fault so wouldn't like to say. Potentially you have a misfire
@@RJW_Customs will try change the tandem pump as it presurises the fuel injector maybe causeing misfire but have no codes
And had it on vcds all injectors within spec
Thanks man
Your welcome
Does this pump power the injectors up too
By power do you mean electrical supply yo fire the injectors or supply fuel pressure to them?
@@RJW_Customs supply fuel pressure them
@@abdulbeany1894 yes supplies the injectors with fuel pressure
@@RJW_Customs thanks for your help will get it changed
#vagfanboy, nice vid 👍🏻
Forever ha ha
Not mentioning whether the fuel system needs priming or not after reinstalling the pump on the engine => downvote
Pretty sure I say about cycling the ignition several times to re prime the fuel system?