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MG Midget and Sprite Technical - HIF 44 rubber gasket trick

I have an HIF 44 carb, and have just removed the bottom plate to clear some debris. Whereupon the square section rubber seal popped out of its groove and extended itself so now appeears to be about 1/2" bigger circumference than it was a moment before!

Is there a trick to shrink it back to its proper size?
This is not a problem I have come across before! (obligatory smutty joke content)


Guy Weller

That is what they normaly do!!

The new ones are perfect size but on contact with fuel they expand.
good for sealing the float chamber not so for re fitting.

Never had a trick to refit.
just jogled around until it would.
Onno Könemann

I used a little vaseline to help hold it in place - worked for me
P Willoughby

I thought someone might have some "cunning plan" to shrink it down again - maybe soaking it in ethyl alcohol or some-such.

I tried the vaseline idea but there is still just too much of it to get it to lie down!
Guy Weller

leave it out in the open air for a while

sometimes they will shrink under exposure to real atmosphere

I feel for you

"been there, tee shirts galore, everyday hazard in the eighties and onwards with HIF equipped cars"

went with the job...
bill sdgpm

Thanks Bill, You are absolutely right! It has been airing now since 3pm and is just about back to normal. At least it will now push back in.

This is yet another "sulk" from my car for not having been driven for all of 3 weeks during the re-spray. I thought I had sorted them all out but then this morning the float needle decided to stick open. Is there an easier way on a HIF than removing the base plate?

I realise now that my last post does look a bit suspect for the BBS - if read out of context!

Guy Weller

I had the bottom plate off the HIF6 on my MGB a number of times and I never had a problem with an expanding seal.
Dave O'Neill 2


and you dirty boy!
go wash the fingers you typed that text with ;P
Onno Könemann

I usually just took off the carb (4 nuts and washers) and worked on it upside down usually with most pipes and cables still glued on

SO much easier to reach DOWN and fix the needle valve

(mind you, back in those days there were Rover dealerships everywhere to buy new viton tipped needle valve kits from, bet it's a stack harder now)
bill sdgpm

Or you could just fit a new one (AUD3588A). 1.20 to save a lot of hassle sounds a good deal to me.
Paul Walbran

Maybe next time Paul,
For now just letting some fuel wash through it seems to have done the trick so I presume it was a bit of crud. Fingers crossed!

I didn't remove the carb, just the air filter and the 4 up side down screws for the bottom plate. Easy enough with a stubby screwdriver
Guy Weller

Guy Weller:
I am thinking about removing the bottom cover of my HIF44 which is on a Titan manifold - I sourced it years ago from your side of The Pond, possibly from a Metro (?) - I doubt that it has ever been removed and/or cleaned...I don't want to get into a major rebuild process and lose what is left of the summer season...

My question is: How hard was it to replace the rubber gasket leaving the carb on the manifold...does the rubber gasket sit in a groove or recess?

I have attached a screen shot and indicated to be what I believe to be the correct part...

Thanks for any advise on working upside down...

Mike P.
Buffalo, NY

Mike Pelone

My carb is the same set up as yours, and also on a Titan manifold.

In my case the car had stood unused for about 3 weeks whilst I was working on a respray and it rather took a sulk about this. Mostly electrical problems but the carb also started overflowing. I thought this was most likely to be a bit of debris in the needle valve and the easiest solution is to remove the bottom plate to drain the float chamber and to let fuel run through to wash the valve seating clean. anyway I did this and it worked fine.

I wanted to disturb the least possible so I left the carb in situ. I removed the air filter to give better access and undid the 4 screws using a short- handled "stubby" screwdriver. The bottom plate (32) and gasket (33) just come away. There was a little sediment in the bottom which needed rinsing out.

The only difficulty I had is as I posted here- the gasket had swollen in the fuel and was apparently too large to go back into its groove! But as always, advice here was good. I left the rubber gasket to air-dry and it shrank back down to a perfect fit. I did use a little Vaseline to hold it back in place and help achieve a good seal.

Easy job refitting the screws. Just remember the base plate only fits one way around so take note as you remove it.

Only other comment is that if doing anything more than just rinsing out the float chamber, then it would be quicker and easier to unbolt the carb and deal with it on the bench

Guy Weller

This thread was discussed between 09/08/2010 and 10/08/2010

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