HI, common problem, but you don't say which engine, the piping varies a bit between them, however is it a metal pipe or a rubber pipe? Simpler if its a rubber pipe or a seal to a metal pipe that has failed! Best to check the diagrams for the cooling system and/or rear heater from the diagrams available here
http://lushprojects.com/bongopartsmk2/ Replacement parts from either eBay or one of the dealers can normally help;
These companies do a range of spares, not all will have everything so try them all;
For smaller parts its probably best to ring companies as not all the smaller parts make it on to the web sites!
SPARES:
Bongo Land
www.bongoland.co.uk/shop/ 0114-2550836
Bongo Spares
www.bongospares.co.uk/ 01422-823249
Vosper Parts
https://vospersparts.com/ 01752-636494
Auto Jap Spares
www.autojapspares.com/ 02476-474848
AutoLinkUK
www.autolinkmx5.com/ 01556-509088
SALES & SPARES;
Bennetts Bongos (Stafford)
www.bennettsbongos.co.uk/ 07976-925843
Ian Taylor UK (Stoke on Trent)
www.japcarimport.co.uk/ 01782-594125
Southern Bongos (Southampton)
www.southernbongos.co.uk/ 02380-733995
Stephen McWhirter Services (Cumbria)
www.stephenmcwhirter.co.uk/ 07585-304362
Dore Service Station (Sheffield) doreservicestation.co.uk/ 0114-2364691
Fred the Bongo Man (Newbury) Shamrock works. Andover Road, Ludgershall, SP11 9PE
www.fredthebongoman.co.uk/ 077757-34328
Derwenthaugh Motors (Newcastle)
www.derwenthaughmotors.co.uk/ 07596-862711
Bongomaster (Leicester)
www.thebongomaster.co.uk/ 07873-314519
Doctor Bongo (Plymouth)
www.doctor-bongo.com/ 01752-224651
Bongo Barn (Northumberland)
www.bongobarn.com/ 07989-709942
BREAKERS:
Milton Gough's (Barnsley)
www.facebook.com/Miltongoughs 01226-725356
Bongo Parts (Billingshurst)
www.bongo-parts.co.uk/ 01403-741913