*NOW BOOKED FOR 2026* Transitmania 17 @ Santa Pod 17th to 19th July 2026 *ALL DETAILS HERE*


Lucas cav pump leak

Transit Mk3, 4 & 5(smiley front) Forum. All Transits 1986 - 2000

Lucas cav pump leak

Postby Lyntransit » Fri Aug 08, 2025 2:47 pm

Hi my transit pump is leaking underneath i put .y hand down and it's behind a component with a spring at the rear of it. It seems.s it's leaking past the spring. I have took a video of it but don't know how to post it.ive entered a pic it's the part worn nut on the end. It's at the rear of that and has a spring at the back of it. Any help would be grateful
You do not have the required permissions to view the files attached to this post.
Lyntransit
Transit Addict
Transit Addict
 
Posts: 26
Joined: Fri Aug 08, 2025 2:29 pm


Re: Lucas cav pump leak

Postby Lyntransit » Sat Aug 09, 2025 9:31 am

Hi thanks for advice. It would be ideal if I could get someone in the Leicester area to possibly have a look and fix it for me. I'm OK with basic stuff but diesel isn't my thing lol . So a big shout out for anyone who could help. Thanks lyn
Lyntransit
Transit Addict
Transit Addict
 
Posts: 26
Joined: Fri Aug 08, 2025 2:29 pm

Re: Lucas cav pump leak

Postby Mislaid » Sat Aug 09, 2025 12:38 pm

It is awkward, but can be done without pump removal.
Advance housing is held on by 2 bolts underneath.
Put a container underneath, first, to catch the diesel that will leak out,
Mislaid
Transit Aficionado
Transit Aficionado
 
Posts: 115
Joined: Sat Feb 27, 2016 2:40 pm

Re: Lucas cav pump leak

Postby V184 » Sun Aug 10, 2025 8:48 pm

Lyntransit wrote:Hi my transit pump is leaking underneath i put .y hand down and it's behind a component with a spring at the rear of it. It seems.s it's leaking past the spring. I have took a video of it but don't know how to post it.ive entered a pic it's the part worn nut on the end. It's at the rear of that and has a spring at the back of it. Any help would be grateful



Unclip the plastic rod and unscrew the large nut, used to come as a replacement kit from Lucas
User avatar
V184
Transit Fanatic
Transit Fanatic
 
Posts: 3633
Joined: Thu Jun 08, 2006 8:16 pm
Location: You're right, V184 is a God !

Re: Lucas cav pump leak

Postby Lyntransit » Mon Aug 11, 2025 1:23 am

Hi thanks. Does the fuel selonoid just un scew and refit new one? Also the two bolts just unscrew to expose gasket?. Cheers
Lyntransit
Transit Addict
Transit Addict
 
Posts: 26
Joined: Fri Aug 08, 2025 2:29 pm

Re: Lucas cav pump leak

Postby Mislaid » Mon Aug 11, 2025 11:49 am

This parts diagram is very useful for understanding how pump goes together

https://injectionpumps.co.uk/interactiv ... iagram.htm
Mislaid
Transit Aficionado
Transit Aficionado
 
Posts: 115
Joined: Sat Feb 27, 2016 2:40 pm

Re: Lucas cav pump leak

Postby V184 » Mon Aug 11, 2025 1:23 pm

Lyntransit wrote:Hi thanks. Does the fuel selonoid just un scew and refit new one? Also the two bolts just unscrew to expose gasket?. Cheers


Yes simply unscrews and fit replacement which used to come fitted with seals etc
User avatar
V184
Transit Fanatic
Transit Fanatic
 
Posts: 3633
Joined: Thu Jun 08, 2006 8:16 pm
Location: You're right, V184 is a God !

Re: Lucas cav pump leak

Postby Lyntransit » Tue Aug 12, 2025 4:14 pm

Hi does the selonoid hold fuel because it looks like it's coming from that. To the left of that selonoid ( as you look at it straight on ) there is a bolts that if put paper towel around it it slows the drip down. Unless it's got a washer that's broke and it's spraying fuel onto selonoid making it look like it's the selonoid. When I brought the van a nd started it up I did notice it dripping fuel but it stopped after about 2 mins so got it cheaper and now it's constant drip. Teach me lol
Lyntransit
Transit Addict
Transit Addict
 
Posts: 26
Joined: Fri Aug 08, 2025 2:29 pm

Re: Lucas cav pump leak

Postby Lyntransit » Mon Aug 18, 2025 3:15 pm

Hi everyone does anyone know any body who can help with. Y leaking pump. In the Leicester area. I need someone who can fix it. I haven't a clue on diesel pumps. I know you can get kits to refurb them but I'm not confident enough to attempt it. Thanks for reading
Lyntransit
Transit Addict
Transit Addict
 
Posts: 26
Joined: Fri Aug 08, 2025 2:29 pm

Re: Lucas cav pump leak

Postby Harvy » Mon Aug 18, 2025 4:33 pm

Lyntransit wrote:Hi everyone does anyone know any body who can help with. Y leaking pump. In the Leicester area. I need someone who can fix it. I haven't a clue on diesel pumps. I know you can get kits to refurb them but I'm not confident enough to attempt it. Thanks for reading


Hi mate. I don’t know this company by they have some pretty good reviews on google and one of them even mentions a cav pump. They might be worth a try.

https://www.welhamgroup.co.uk/
2010 T350 LWB H3 RWD 2.4 115 Full poverty spec! :D
Harvy
Transit Aficionado
Transit Aficionado
 
Posts: 254
Joined: Sun Oct 06, 2024 9:02 am
Location: South Yorkshire

Re: Lucas cav pump leak

Postby Lyntransit » Mon Aug 18, 2025 6:17 pm

I did ring the. And they said take pump off and take it to them for refurb. I e got the tools just need someone to tell me how to remove it. Timing etc. Cheers
Lyntransit
Transit Addict
Transit Addict
 
Posts: 26
Joined: Fri Aug 08, 2025 2:29 pm

Re: Lucas cav pump leak

Postby Lyntransit » Mon Aug 18, 2025 8:09 pm

I've ordered the bits ie plunger. Advance o ring and housing gasket. Got one bolt out the 19mm but other one is a b### to get on. Is it a different size ?
Lyntransit
Transit Addict
Transit Addict
 
Posts: 26
Joined: Fri Aug 08, 2025 2:29 pm

Re: Lucas cav pump leak

Postby Lyntransit » Thu Aug 21, 2025 3:11 pm

Hi fitted new plunger. Sel and gasket but still leaking. It's not from the gasket. It seems still coming from back of housing where plunger fits. I fitted new rings around the big nuts at back a few front. Is there anything that can cause the leak from plunger end ?thanks
Lyntransit
Transit Addict
Transit Addict
 
Posts: 26
Joined: Fri Aug 08, 2025 2:29 pm

Re: Lucas cav pump leak

Postby Lyntransit » Fri Aug 22, 2025 9:51 am

Hi what can make fuel out of plunger end ?on the exploded diagram there is something between spring and plunger i haven't got that bit and its not listed but I can't see why it leaks from plunger. The only thing I've noticed is the piston is worn. I've noticed advance housing and piston on sites does it matter if I fitted that ? As long as its from a dps. Wish it was easy. Cheers
Lyntransit
Transit Addict
Transit Addict
 
Posts: 26
Joined: Fri Aug 08, 2025 2:29 pm

Next

Return to Mk 3, 4 & 5 - Second Generation Transits



Who is online

Users browsing this forum: No registered users

This site contains affiliate links for which we may be compensated.