Bleed­ing diesels

Car Mechanics (UK) - - Help! -

How many dif­fer­ent ways are there to prime diesel en­gines? Gino Pi­nar

There are ba­si­cally three dif­fer­ent meth­ods. The first is for ve­hi­cles with a hand primer built into ei­ther the fuel fil­ter or fuel line, which can be used to bleed the sys­tem through. The sec­ond method for ve­hi­cles equipped with a low-pres­sure elec­tric sup­ply pump is to re­peat­edly turn the ig­ni­tion on and off. When the ig­ni­tion is turned on, the sys­tem will ini­tially ac­ti­vate the fuel pump to prime the sys­tem. Un­less the en­gine is run­ning or crank­ing, this ini­tial burst will cease af­ter a short time. Turn­ing the ig­ni­tion on and off re­peat­edly will utilise this ini­tial burst of fuel to bleed the sys­tem.

The third method is used when there is no elec­tric pump fit­ted and no builtin primer in­cor­po­rated in the sys­tem. Here, a syphon is used to draw the fuel through the fil­ter af­ter re­place­ment. Very of­ten the syphon can be placed on the re­turn pipe from the high-pres­sure fuel pump, to draw the fuel through the com­plete sys­tem in­clud­ing the en­gine fuel sup­ply pipes.

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.