I have seen many references to the connector on the end of the plenum, that takes the Vacuum pipe from the brake servo, on a number of forums. In each case the question has been mainly about how to get the pipe released from the connector and in some about getting spares. Numerous replies have stated that 'the pipe cannot be released' or 'it is not available as a replaceable part' some wise posters have also used their wisdom to state 'I don't think it was ever designed for the pipe to come out' and proceeded to go into complex details of how to cut the pipe and use various connectors to rejoin it . Well after find a source for the part I can categorically state, the part is readily available and easy to repair.

So first for all those out there who have been totally perplexed by this simple method of releasing the pipe read on;

Simply press in the red retaining ring, around the end of the pipe, see photo below, and at the same time withdraw the pipe. Simples...tch!



Now for those in the advanced class we move on to repairing the connector while the rest catch up :lol1: :lol1: :lol1: . This is part number LZN100220 available from Rimmerbros (to name but one source) at a cost of £10.80 inc. Tax A similar part no. is LZN100390. This part is not listed for the Land Rover but is for MG Rovers and Minis.

It is not absolutely necessary to remove the original connector as the 'O' ring and red retainer can simply be swapped over unless there is other damage to the original, such as trying to pry or twist it out. But I wanted to see how fitting the new one could be done and so heres how to do it.

1. Disconnect the throttle cable and (if you have cruise control (CC)) the CC cable. Release only the lock nut on the right side of the bracket enough to pull the outer cover back and off the bracket (moving the other nut will upset the adjustment of the cables).

2. Disconnect the throttle body heater pipes, (a good opportunity to fit a new gasket here while the Plenum is off).

3. Disconnect the: Idle bypass valve hoses, the purge valve pipe and valve cover breather pipe from the throttle body.

4. The Heater pipes are connected to the side of the plenum and need to be released.

Now the most difficult part which arguably need not be done, but it makes it easier to refit the Plenum if you do it and you will not run the risk of damaging the upper inlet manifold gasket or scratching the mating face of the plenum. I have done it both ways in the past and despite the hassle find it better to carry out the next procedure.

5. At the rear of the inlet manifold loosen the bolts securing the Coils to the Inlet manifold, just enough to allow the plenum to be withdrawn past the bracket.

Boy that was a bitch, now

6. Release the Idle bypass valve and purge valves from their respective brackets and remove the air intake hose with MAF. (be gentle with the MAF it doesn't like being manhandled)

7. Now with all those ancillaries released we can remove the 6 bolts securing the Plenum to the manifold, one at each end and 2 on each side.

8. Lift off the plenum and move it to your work bench. Give it a good clean while you have it off, inside and out and take a look at that throttle body heater gasket if there are signs of leaking coolant around it you may want to take tis opportunity to fit a new one.

9. Remove original vacuum pipe connector. This can only be done this way as the fitting is like a push fit plumbing connector but with the retaining grip ring on the out side and there is no way to retract them.

a. Plenum on the bench



b.Holding plenum on end, open throttle valve and position a suitable drift on the inside of the connector.



c. With the drift in place use a soft face hammer to gently knock out the connector. It does this by breaking the grip of the adhesive joining the two halves of the fitting.



d. The inner part of the fitting remains in place and needs to be pushed into the valve body and retrieved.



So you will end up with these remains when your finished



e. Time to fit the new fitting. Take off the red part and put safely aside. Now use a smear of oil on the fittings external 'O' to ease insertion



f. press in fitting as much as you can manually



g. Now gently tap home with a soft face hammer until the main body is flush with the surrounding metal



h. Refit the red lock ring and if you removed it as well the 'O'



All done now refitting is the reverse of removal. You will need to research the torque setting and buy; LZN100220, upper inlet manifold gasket and throttle body heater gasket.

Can I also take this opportunity to say that while you are here and have access to the injectors it would be worth while changing the injector seals. these are a source of air leakage on the intake side and unless you have done yours are often over looked on the V8 and if they have been there since the car was built are well over due a change. I did mine a couple of months ago and it cured the lean mix fault I was getting on Bank 1 which I had been chasing of months.

 

Very informative. Thank you for taking the time to write this up, my man

 

Great write up and thanks for stopping me before trying to remove the old plug with the intake on. All you need is the red retaining ring.