Classic Ford Weber Dgv Rebuild Instructions

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120 November 2008

Rebuild Your

Weber DGAV Carb

1

Remove the float pin with a small screwdriver, or if

tight gently tap a small punch with a hammer.

Then remove floats and float needle valve.

4

Now you can start stripping. Firstly remove the

circlip for the choke butterflies with a small flathead

screwdriver. Take care not to slip.

2

Test the power valve diaphragm by pushing down

on the spring and blocking the small airway on the

face surface. If the diaphragm is good the vacuum

created will mean the spring will stay compressed,

if it doesn’t the power valve will need replacing.

5

Then undo the six screws that hold the top on, and

remove the top of the carb from the main body. Be

careful as the screw heads are fairly soft metal.

3

Remove the power valve diaphragm by undoing

the three flathead screws that hold it in position,

and take a closer inspection. This one’s really had it.

November 2008 121

6 7 8

Then undo the 19 mm filter plug and remove the

old filter. Remove the 10 mm float needle valve

seat and the top half is ready for cleaning.

Now move on to stripping the main body of the

carb. The first thing to go is the old gasket.

Overhauling a 32/36 DGAV is the perfect way to get all the benefits

of a brand-new unit at a fraction of the cost. Here’s how to do it...

Words Jamie King Photos Jon Hill

he Weber 32/36 DGV and

DGAV carburettors were fitted to

a whole host of classic Fords, and

many have since been retrospectively

fitted as a useful performance upgrade.

The carbs are easy to set-up and

maintain, however like most things in life

they do benefit from some tlc from time

to time – either a service or a full rebuild.

Fortunately, service kits and replacement

parts such as jets, diaphragms and valves

are all still readily available from the likes

of Webcon direct and Weber dealers.

You may be lucky enough to only need

the service kit which can be fitted without

too much fuss, but for a ‘proper job’ you

will need to do a complete overhaul.

We took our 32/36 DGAV to

carburettor specialists and Weber dealers,

Northampton Motorsport in, er,

Northampton for the guys in the know to

show us exactly what’s involved with

turning a gunked-up, 30-year old

carburettor into a nice, shiny, all-singing

all-dancing, overhauled unit.

Here’s how we did it...

TCosts:

Service kit £41

Power valve

diaphragm £18

Choke pull-off

diaphragm £13

Teflon bearings

(fitted) £30

Complete overhaul

incl service kit £152

Info

CONTACTS

Northampton

Motorsport

01604-766624

www.northampton

motorsport.com

Webcon

01932 787100

www.webcon.co.uk

Strip-down

Before stripping wire bush the base of the

carburettor to reveal the part numbers stamped.

These identify the carb and are needed to order

the correct replacement parts. In this case it is a

32/36 DGAV ‘3D1’.

CFTECH carb rebuild

122 November 2008

CFTECH

November 2008 123

Remove the air corrector jets from the top surface

and the main jets from the float bowl. Also remove

the emulsifying tubes from under the air jets. It’s

worth writing down which size jets came from

which place to ensure fitting them correctly later.

9

Remove the idle jet and progression jet from the

sides of the float bowl.

10

Now remove the accelerator pump jet and

delivery valve from the centre of the main body.

Remove the power valve from the float bowl. Now remove the accelerator diaphragm and

enrichment device from the sides of the float

bowl, and remove the mixer screw from the side

of the main body. (Some DGAVs do not have the

enrichment device).

Remove the automatic choke housing (on the

DGAV). If the unit works leave it alone as trying to

repair them usually ends up with the centre bolt

shearing off. If that happens the only way forward is

to convert to manual choke as replacement auto

choke parts are not available.

Then remove the three screws that hold the choke

pull-off diaphragm in place and remove the

diaphragm itself. Check it is in good condition, if

not a replacement will be needed. Then remove

the choke unit from the main body by undoing the

three retaining screws at the side.

Turn the carb over to see the throttle butterflies.

Remove the locking tab and 12 mm locking nut that

holds the throttle shaft in position. Before removing

the linkages and springs either write down or take a

photograph of the order they come off in to help you

remember how it all goes back together.

Undo the two screws that hold the butterfly in

place and remove the butterfly. If they are tight

gently tap with a hammer to loosen.

11

12 13 14

15 16 17

Then remove the throttle shaft from the main body

and check for wear. Repeat steps 16 and 17 for the

secondary shaft, remove and then check for wear.

Finally remove the auxiliary venturis by hand or

gently persuade with a pair of pliers.

19 Rebuilding18

Before reassembling the carb Northampton

Motorsport carry out a couple of trick mods. Firstly

the base of the carb is machined totally flat to ensure

a perfect seal with the spacer block. Also the body is

reamed to accept Teflon bushes between the body

and throttle shafts.

The next step is to fit the bushes. Patience is

needed as they can be very tricky.

Now refit the throttle and secondary shafts into the

main body. A drop of oil helps lubricate the shafts and

makes life a little easier.

Refit the throttle butterflies and reassemble the

throttle shaft linkages and springs in the reverse

order to the way it was disassembled.

Next refit the auxiliary venturis. If they are loose they

will rattle and will not work, so gentle tap the body

with a hammer and punch to secure them in place.

Before refitting the jets and emulsifying tubes

replace the old O-rings with new ones from the

service kit. Refit the jets in the same position you

marked down earlier in step 9.

20 21 22

23 24 25

One stripped carb ready for thorough cleaning

before reassembly. To clean the carb you can use

carb cleaner but for a better finish professionals

like Northampton Motorsport have all the parts

chemically cleaned.

carb rebuild

124 November 2008

CFTECH

Refit the accelerator pump jet and delivery valve in

the centre of the main body.

Next refit the enrichment device and accelerator

pump, replacing both diaphragms with new items

from the service kit.

Refit the auto choke unit replacing the small green

O-ring for the new one from the service kit...

...then screw the choke unit to the main body, refit

the choke pull-off diaphragm, and refit choke

housing. If the old diaphragm was perished new

items are available from Northampton Motorsport.

Next refit the mixture screw in the side of the

main body, replacing the O-ring with a new item.

To roughly get the right mixture wind the screw in

all the way then unscrew by two turns.

Refit the power valve diaphragm and float needle

valve into the top of the carb then the filter with the

new item from the service kit and replace 19mm

filter nut. Once again new diaphragms are available.

The next job is to refit and set-up the floats. Plastic

floats need to be 35 mm from the surface and

brass ones need to be set-up at 41 mm.

To adjust the distance between the float and the top

of the carb gently push on the float tab with a

screwdriver to bend it to the correct position

Fit the new gasket and refit the top of the carb to

the main body. Be careful to make sure the floats

stay as you just set them.

26

29

32

36

33 34

30 31

27 28

The final job is to refit

the choke linkage and

circlip, and set up the

automatic choke unit

– to do this loosen the

three screws that hold

the choke housing and

rotate until the choke

butterflies are set

correctly. This can be

tricky as locating the

housing correctly after

rotating it means

loosening the centre

bolt, which often snaps.

One finished carb,

ready for action and a

lot cheaper than the

price of a brand new

unit. Lovely.

35