Hi guys,

I have a Fiat 500 1.3 Multijet. I've had the car going onto 3 years and it's around 103k on the clock. I normally carry out my own servicing and small repairs. Yesterday I when I popped the bonnet, I noticed a strong smell of diesel. After further inspection, I noticed that there was an amount of diesel on the gearbox and some on the floor.

I've done some research and the high-pressure pump is known for its seals wearing and then slowly leaking diesel. I'm almost certain it's coming from that area. Just wanted some advice, if anyone on here has carried out the Fuel pressure pump replacement seals job? I've seen a few videos on Youtube, it seems pretty straight forward. As the seal kit is £24 and a recon pump is around £160.

I've recently just spent £800 on a gearbox replacement and can't afford to take much more of a hit on the vehicle, which is why I'm going to try the repair myself.

Anyone got any advice?

Nope... I had a leaky pump bt it turned out to be one of the fuel line connectors. A new connector solved it.

But it did look DIY-able, when I researched it. It'll be interesting to know what went wrong/how you get on..


Ralf S.

Was it the fuel line connector going into the high-pressure pump? Part of me thinks, when it went into the workshop for the gearbox, that they might have damaged one of the pipes, as it wasn't leaking before it went in and strangely a few days after. It could possibly be that as it sits right on top of the gearbox.

Just cleaned up around the area of the fuel pressure pump and the fuel line on the left is leaking from the seal. Can I replace the seal from top or will I have to dismantle the entire pump?

Nbhad said:

Just cleaned up around the area of the fuel pressure pump and the fuel line on the left is leaking from the seal. Can I replace the seal from top or will I have to dismantle the entire pump?

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I'm trying to work out what that bit is.. but my leak was caused by essentially a loose hose clamp. No idea why it suddenly decided to go incontinent... but the rubber pipe presumably pulses with the pressure in the lines, so it could just eventually ease the clamp loose.

I had a spare new OE style clamp the right size so I fitted it and it solved the problem. If you have a Jubilee clip that would do ... but use some thread locking compound in the worm drive (or stuff some silicone sealant in the threads) to stop it coming undone. The Fiat style squeezed on clamp style is better for here.

For good measure I also put some silicone sealant around the stem that the rubber hose fitted over, where the clamp would go (but veeeery careful not to allow any of it to get into the pipe). That solved the leak.


Ralf S.

It's not the one on the right, that's the one that has the Jubilee clamp style hose. It's the one on the left which comes from the fuel filter and it's the same style Fiat quick release connector. The area is not the quick release pipe going into the connector, it's where the connector sits into the pump housing. I can see it's leaking from the seal area. What I'm struggling to do is to remove the T25 screw as it's heavily rusted and extremely tight. I tried it once with WD-40 and the ends of the heads started to round due to the rust. The last thing I want to do is round off the screw, any suggestions?

My thought was to just put silicone around the end and stick the bracket back on. I've messaged XR8 who supply seals for the Bosch CP1 and they don't supply the seal for fuel connector going into the housing. Done some research on eBay for second hand and recon units and the majority of them don't supply either connector for the low-pressure line and the return feed or the bracket that supports either of the two.

Ah.. I can see it better now. I don't have a 1.3 (I'm 1.9) and it's slightly different.. but your jobbie is the same setup as the fuel pump connectors on a regular (on top of the fuel tank) fuel pump.

What's almost certainly happened is that the metal clamp was fitted slightly touching the plastic end connector. As the engine vibrates, the clamp frets against the connector and eventually wears through it.

When you remove it you will see that the clamp has shaved away the plastic and you'll have a pin-hole.

There's no "easy" cure. The way you would fix it if anything was possible is to remove the plastic connector from the fuel line and fit a new one. Job jobbed.

But the connector;

a) Can't be removed from the pipe. It's high pressure, so very bonded in.

b) Even if you cut the pipe off at the joint and pull it through a bit.. you can't get new connectors (or someone please post a link).

My advice is visit a scrapper and find a seconda-mano fuel line and connector .. but inspect it to check the clamp hasn't fretted that one too. It depends entirely on how they're fitted.


Regarding the clamp.. if the bolt is rounding off inside (usual!) then you might have to remove the whole pump with the fuel pipes attached. Then use an impact driver or a little socket/T25 on the end of an air-gun (might be less brutal to the pump). If all else fails, amputate the screw and/or clamp and then use a stud extractor or drill, depending on how much stub is left, to remove it.

The clamp (see if you can get another one when you trace a second-hand fuel line, though I'd guess new ones are also available) is essential. It stops the connectors popping out. There's nothing except an O-ring holding them in the pump. Glue or epoxy is not going to do it, since it doesn't stick to diesel-covered plastic. You need to bolt the clamp down.

Sorry it's not a good answer but the good news is that it could be a fairly cheap, just a bit fiddly fix.



Ralf S.

Thanks, Ralf. I was under the impression the left fuel line was a return line as it has a quick release connector same as the one you find on your fuel filter.

I went over to a local garage yesterday and the chap was saying to me that I wouldn't recommend doing the job yourself as the cam end of the pump is timed with the chain and the entire camshaft, is this correct? everywhere I've looked, I've not seen this information anywhere. I also managed to get ablow out of the connector and the washers. Not really sure what to do.

I'm not sure which fuel line is the high pressure one, and which is the return but it doesn't matter, since the pipe/connector ends are made the same way and they're designed for high pressure so not easily seperated from the pipe.

The diagram is interesting since it suggests you can get the connector (no. 27) separately.. but now I'm not sure what all the other parts (no's. 20, 25, 26 and 35) do. They may be appended to the end of the connector (27) and do "something" but in that case, they would probably come out with the connector, if you remove it.

As far as I know/expect, the connectors (27) are simply pressed into their hole in the pump, sealed by an O-ring.. and the yoke clamp (no. 80) keeps them both from coming out.

It's a shame your bolt 79 is rounded off otherwise you could try to remove the clamp and see if the connector comes out, so you can confirm that it's as I think, that the clamp has worn a hole in the connector through fretting.

It sounds like it's a "bad idea" to remove the pump from the motor but theoretically if you pull it out without touching the engine (esp. not turning it over... but why would you) then you should be able to slide it back in when you've finished and it would be "timed" as it is now.

But I'd guess the pump just has a key on its shaft that slots into a notch on the camshaft (or similar) to help them mate up and not spin. I can't imagine for the life of me why Fiat would need the pump "timed" with the cam-shaft. It's way more likely it just has to be bolted to it, so it goes round when the camshaft does.

Anyway... if it was me, I'd still attack that bolt (probably in situ' if you don't want to remove the pump) to remove it, then the clamp, to see if the connector is worn through. Then it'd be a simple case of just replacing the fuel pipe (if you can't separate the connector or find a separate one) complete with a new connector on the end.

Ralf S.

Thanks, Ralph. I really appreciate all your help and input. Just been ringing around and doing some research, I've managed to find a few youtube videos of when they take the pump apart. I've attached an image of what holds everything in place. I've looked around for the seal kit that contains the part that I need, no luck anywhere. Contacted a local diesel pump specialist and they're charging around £200 to recondition the pump.

I tried contacting Fiat about the pipe but they don't seem to have in on their systems. I've attached an image of what they sent me and I can't see the pipe anywhere. My worry is, I'm either somehow going to need to get the supporting bracket off even if I do I can't find the part I need. Or stick a 2nd hand unit in, but only god knows how long that will last. Last option is to get mine reconditioned and fingers crossed I have no issues taking it off.

At the moment I'm just driving around as it is. As it's not really affecting fuel economy or the way the car drives. I know i need to get it sorted sooner rather than later but just can't afford much on the car after the gearbox.

That photo gives a good view.

The connector on the left, in the picture, with the cut off hose (which on your pump is the one that's not leaking) seems to have a hose-clamp on it, so it would be relatively easy to remove the pipe from theconnector and stick a new connector (if you could find one) on the end of your pipe.... (or a good, second-hand connector taken off the end of a second-hand pipe).

You would still need to remove the yoke clamp screw to get the connector out of the pump.

The right hand one (which on your car is leaking) looks slightly different but in the photo you can see that the hose has definitely been removed from the connector, apparently without breaking it. If so, it should also be possible to remove yours.. although as you say, there's no point in dismantling it until you have a new connector and you also managed to get the clamp screw unbolted in order to take teh connector out.

The diagram FIAT dealer gave you shows the pipes. The pipe leading to that connector is part number 55216330 but it may or may not have the connector on the end. In the diagram the connector appears to be part of the pump assembly, so if you ordered a new pipe, you would probably not get the connector (although sometimes parts can surprise you).

Your first job is to get that clamp off for a better look and confirm it is really a leaky (holed connector). You can re-fit the clamp with a new bolt once you've had a look. I'd take it to a mechanic to undo.. they have the knack/stud removal equipment to take out that rounded off screw without belting it too much.. and it shouldn't cost too much.

Once you know it's a knackered connector, get onto the breakers for the part you need.


Ralf S.

Hello Ralf,

Good news, after some perseverance I managed to undo that bolt and removed the bracket. The connector pops right off. Also, the one on the right is just a quick release fuel line, same as the fuel filter (which has 3). I didn't remove the entire connector off as I didn't want to disturb anything until I need a new connector or a new seal.

Everywhere I've looked I just can't find the seal or the washers I need. I thought about putting PTFE tape around it, as a short term solution, until maybe I can source the part I need. Do you think it's a good idea putting PTFE tape around it?

PTFE is used to line fuel lines so the tape should be inert to diesel (and maybe also petrol.. although petrol is more aggressive as a solvent).

The worst thing that can happen is that the tape dissolves and clogs the pump... but as long as you just wrap it round the o-ring so that any melted tape can't get sucked into the pump then it can't be worse than it is now.

Where is the leak coming from? Is the connector holed or worn through, or is it simply leaking at the o-ring? Any correct size o-ring ought to fix it, if it's just the o-ring.


Ralf S.

Just a thought, would a hydraulic pipe company, like say Pirtek have a suitable seal/fitting I agree they're more industrial in the size of fittings.

Ralf S. said:

PTFE is used to line fuel lines so the tape should be inert to diesel (and maybe also petrol.. although petrol is more aggressive as a solvent).

The worst thing that can happen is that the tape dissolves and clogs the pump... but as long as you just wrap it round the o-ring so that any melted tape can't get sucked into the pump then it can't be worse than it is now.

Where is the leak coming from? Is the connector holed or worn through, or is it simply leaking at the o-ring? Any correct size o-ring ought to fix it, if it's just the o-ring.


Ralf S.

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As far as i can see the connector looks fine. It looks like it's leaking from the o-ring and only leaking small amounts of diesel. I know what you mean about it getting sucked into the pump, but i'm thinking of applying just above the o-ring and some around where the connector sitsinto it's base.

John202020 said:

Just a thought, would a hydraulic pipe company, like say Pirtek have a suitable seal/fitting I agree they're more industrial in the size of fittings.

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I've contacted a few local companies that supply fitting for and seals and connectors for diesel pumps. Just awaiting their response.

I would remove the O-ring (without snapping it, if it's slightly cracked/perished enough to be leaky) and wrap a layer of tape inside the O-ring groove itself. Cut off any excess and then refit the O-ring.

The aim would be to make the interfaces between the O-ring and the connector, and the O-ring and the pump receiver *a bit* more snug.

If you wrap the tape just over the O-ring you won't solve any leak between the O-ring and the connector.. and when you put the connector back into the pump receiver, if it's too tight the tape will get scraped off.

But don't over do the tape.. even 0.1mm of additional O-ring "fatness" could be enough to fix the problem.


Ralf S.

Ralf S. said:

I would remove the O-ring (without snapping it, if it's slightly cracked/perished enough to be leaky) and wrap a layer of tape inside the O-ring groove itself. Cut off any excess and then refit the O-ring.

The aim would be to make the interfaces between the O-ring and the connector, and the O-ring and the pump receiver *a bit* more snug.

If you wrap the tape just over the O-ring you won't solve any leak between the O-ring and the connector.. and when you put the connector back into the pump receiver, if it's too tight the tape will get scraped off.

But don't over do the tape.. even 0.1mm of additional O-ring "fatness" could be enough to fix the problem.


Ralf S.

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Hello Ralf,

Got hold of replacement seals for £3 for a pack of 10 so hopefully this weekend going to have a crack at replacing the seal. The same company can get a hold of the connector for £15. Hopefully the seal should fix the issue. I'll keep you updated on how i get on

Just an update managed to source the correct seal for the connector and the large washer that the connector sits on. According to the chap it's classed as a dust cover. Started it up not noticed any leaking as of yet. Just cleaned up all the diesel spill see how the car runs for a week and take a look to see if there's still a leak. I have a sneak feeling that the seals inside the pump have also perished. All in all it's cost me £6 to fix the leaky connector.

That large connector seal would make sense... O-rings are neoprene so don't usually degrade, whereas rubber is a different matter.

Hopefully the new seal will solve the problem.

But you have to post a linky to the item you bought, so other people don't have to search for the same part. It's the rules..


Ralf S.