Vacuum pump

[Bibs 11,654]

Having brakes that still work but make my right thigh like an oak tree isn't fun! I checked my pump last week and got 14mm Hg at the back of the engine bay (throttle jack etc) but it's become worse over the weekend and now the brakes are 'leg' assisted only.

It appears that my vacuum pump has given up the ghost and needs replacing. I don't think it's that hard to swap out but at

[Glyn Harper 55]

I looked at doing this after mine failed the day before the 2004 Oxford meet.. Had to go the whole day with no servo assistance!

An electric one is fairly easy to source and fit.

Only problem is, the vacuum pump pulley and bracket are what is used to put tension on the belt, and this belt also goes to the water pump.

On later cars with an electric vacuum pump, this location was used for the PAS pump.

If you loose your vacuum pump, you'll need another method of tensioning the belt.

I just got a new pump.

Edited July 28, 2008 by Glyn Harper

[Paul93Lotus 7]

Talk to Travis(Vulcangrey)...pretty sure that part can be sourced here on the cheap.

[AJay 1]

If you loose your vacuum pump, you'll need another method of tensioning the belt.

The G cars have a belt that just drives the water pump with no tensioner, this should fit as the distance between the crank pulley and the water pump should be the same.

[Vulcan Grey 251]

the vacuum pump come from an older 80's ford deisel I hear.

I got mine from a NAPA parts store here locally for $100. NAPA #64-1006

A910E9027J GM 78-41746 / NAPA 64-1005; GM 78-44038 / NAPA 64-1006 Vacuum pump (mechanically driven) 64-1005 needs more mods than 64-1006

A910E9027J GM 7844039; GM 781443; AC Delco 215-103 Vacuum pump (mechanically driven) The numbers given are close matches. These parts are being phased out due to obsolescence. Some modifications maybe required. by Tony Grasso. Courtesy of Esprit Fact File (www.espritfactfile.com)

A082M6518F GM 10098493 Vacuum pump, electric

The pump can either fail (sometimes with a loud goose honking or helicopter sound.

Or you could have a leak either near the pump, at the brake booster, or at the controls for the heater in the dash, or at the Tee above the right fuel tank.

The other possibility is that the vacuum pump bracket has broken or fallen out of the car, in that case you would also see the engine temps rapidly rise, since the vacuum pump shares a belt with the water pump.

My website is still down, otherwise I would show you some pics.

Maybe we should talk about your offer Bibs?

Edited July 28, 2008 by Vulcan Grey

[Jonathan 13]

Bibs - if you find something lemme know, I wouldn't mind doing that on the SE too

[Glyn Harper 55]

If you loose your vacuum pump, you'll need another method of tensioning the belt.

The G cars have a belt that just drives the water pump with no tensioner, this should fit as the distance between the crank pulley and the water pump should be the same.

There must be a method on the older cars to slacken off and tension the belt, otherwise you'd never get the belt on or off over the 'v' shape of the pulley.

If you do get an electric pump, you could proably just take the old vacuum pump off with the bracket, and strip it down so it's just the tensioning bracket and pulley left, and not the pump.

Or take the diaphragm out of the pump and leave it there doing nothing.

[sanj 12]

There must be a method on the older cars to slacken off and tension the belt, otherwise you'd never get the belt on or off over the 'v' shape of the pulley.

Brute force and turn the engine with a ratchet on the crank pulley, the belt will lever on. To get it off I suppose cutting it is the best way to go. I just put one on an S4 last week that has a leaky PAS hose, at least he can drive it while I figure out the hose situation.

The electric vacuum pump as used in the S4 is not suitable for the brakes.

Edited July 31, 2008 by sanj

[andydclements 810]

There must be a method on the older cars to slacken off and tension the belt, otherwise you'd never get the belt on or off over the 'v' shape of the pulley.

Sure is.

Undo the 4 bolts that hold the water pump pulley on to the shaft and remove the pulley from the shaft, then take the belt off/ put the belt on, and replace the pulley and 4 bolts.

[AJay 1]

There must be a method on the older cars to slacken off and tension the belt, otherwise you'd never get the belt on or off over the 'v' shape of the pulley.

Nope No tensioner, you wind it over similar to putting a chain on a sprocket.....

http://i245.photobucket.com/albums/gg51/aj...us/DSC00848.jpg

[sanj 12]

Undo the 4 bolts that hold the water pump pulley on to the shaft and remove the pulley from the shaft, then take the belt off/ put the belt on, and replace the pulley and 4 bolts.

In theory this should work, and with the engine out of the car it does, but in situ I found it to be basically impossible.

[Vulcan Grey 251]

I've removed and replaced the WP in-situ a bunch of times.

I always remove the vacuum pump, makes it easier to get access to the WP. I actually remove the 4 bolts of the vacuum pump pulley to make it easier to remove the top pivot bolt of the vacuum pump.

[andydclements 810]

We cheated the other day, we had the gearbox off so could tip the engine enough to get at things in the car to do the WP and use the pulley off method.

[esp88 55]

I had the same problem with vaccume pump and I just replaced it this weekend. It was Not hard work take out/back but for me was hard to swapped the hub for pully !!

After test drive now I can stop!

I also intereset El. vaccume pump, if anybody done that ?

Y.Hotta

[Jamie Garroch 4]

Found this topic after almost experiencing a rear end smash and diagnosing the vacuum pump as the culprit. Tried to order one at the very expensive price of circa £300 from SJ today but not in stock (although he said he could ge one within a week).  So did anyone come across an electric solution?  Looking forward to stopping again!

[Vulcan Grey 251]

look at my posts above.  the pump should be $100

[Jamie Garroch 4]

Thanks Travis. I did see that but was a bit concerned with the use of the word "mods" as that means a whole bunch of different things to folks with varying levels of skills   

 

I'm currently looking at electric which seems to be a similar price as the 'original' (whatever that means in our world!) A910E9027J mechanical pump but given performance would be consistant at any engine speed and probably easier to fit, it might be an interesting upgrade. The UP28 model seems to get a lot of web mentions and appears to be used by several 'large' German marques:

 

http://www.hella.com/microsite-electronics/116.html

 

Anyone got experience of an electric upgrade?

[Vulcan Grey 251]

The NAPA 64-1006 pump is an exact match, no mods or mechanical skills required.  The 64-1005 doesn't have the exhaust port, and some people remove their old port and press it into the new pump, and some just leave it as it is.

 

Both work fine.

 

You just have to unbolt the pulley and the bracket from the old pump and transfer those to the new one.

[Jamie Garroch 4]

Cool . Thanks Travis :-)

 

I did a search for NAPA 64-1006 and GM 78-44038 on http://www.gmpartsdirect.com/ and both came back negative so any ideas for a source?

[Vulcan Grey 251]

ebay!

 

http://www.ebay.co.uk/sch/i.html;jsessionid=63608F5081A3017544DAB1C947C01F9F?_from=R40&_sacat=0&_nkw=64-1006+vacuum&LH_PrefLoc=2&_arm=1&_armm=63&_ruu=http%3A%2F%2Fwww.ebay.co.uk%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D64-1006%2Bvacuum%26_arr%3D1

[Jamie Garroch 4]

Wow. 1/6 of the price. I'd never have found that! Thanks :-)

[Mysterae 270]

Just found this topic, as I reckon my vacuum pump is knackered:

 

 

That's around 7"Hg after build up and dropping to less than 5"Hg when the brakes are pressed. Most vacuum pumps should be in the order of 18"Hg.

 

That ebay link is a big saving on a locally sourced one for sure! I'm still interested in fitting an electric pump though, as most modern cars use them for the brake system and it'll be a lot easier to fit.

 

Few questions:

 

- has anyone fitted an electric vac pump yet? No one has owned up in this thread!

- when fitting and electric vac pump can the existing vac pump just be left in place and in circuit? 

- are there any procedures on fitting the mechanical vacuum pump with the engine still in?

 

Cheers guys.

 

 

[Bibs 11,654]

With the limited access it was much, much easier to take the pump into 3 parts and fit the bracket, then the pump and then the pulley separately.

[Mysterae 270]

Cheers Bibs, do you mean take the pump apart when you say "take the pump into 3 parts"? Sorry if I'm sounding a bit thick!

 

To remove it, do you:

 

- loosen the the pump's mountings to get it loose and the belt off,

- remove the pulley from the pump,

- remove pump (with the carrier plate, item 2 of page 40.27A of the parts manual)

 

I wonder if the bracket that the carrier plate attaches comes off the cylinder block easily? I'm imagine there's something in the way.

 

I notice the pump on ebay is slightly different from the one from SJ's, it has something extra attached to the exhaust port. I'm searching Travis's google images for pictures, as he has pictures of everything!

[Jamie Garroch 4]

I have to admit to buying a very expensive one last week (compared to the eBay remanufactured one) from SJ (which came with a half removed label) and then got my local Lotus specialist to fit it at a cost of 2 hours labour. Well worth it as the car feels brand new now and I can't get under mine anyway due to a sloping drive.