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Bibs

Vacuum pump

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I always loosen the 4 pulley bolts first.  

Loosen then remove the lower pivot locking bolt.

remove the belt.

remove the pulley

loosen and remove the top pump pivot bolt

remove vacuum pump, leaving bracket attached to engine, unless you want to paint it and re-assemble with loctite...

 

BTW I have seen and heard of several vacuum pumps falling out of the car either because the bracket bolts fell out, or the bracket broke.


getting to this top bolt is why I always remove the pulley first.  I used to have a special ground down wrench to fit in this bolt, but it was stolen along with my old car.

 

P4190938.JPG


Travis

Vulcan Grey 89SE

My Lotus Photo and Projects Album

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@ Jamie - who's your local Lotus specialist in Reading? I'm in Swindon so may be handy to know for the future! Shame about the sloped drive, I long for a proper garage rather than working on the drive.

 

@ Travis - to the rescue with an image! Is that from above or below the car? It's been a while since I last looked in that area. I see what you and Bibs are saying now. That black bracket isn't coming off before the vacuum pump or carrier plate. I tried removing the vacuum pump aeons ago and gave up, probably because the pulley was still in place and trying to use a normal hex key to undo that top bolt; no leverage. After you saying about pumps falling out, I'll be sure to check the bracket is sound.

 

Still tempted with an electric one though, like the UP28 from a BMW. Hmmm.

 

Thanks a lot guys, helped a lot!


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The closest (I use to go up to Birmingham!) is now Steve Williams in Maidenhead.  He has a bunch of guys which are more familiar with the later cars but Steve worked on the X180 when he was 'growing up' so there isn't anything that he doesn't know about the Esprit and often gets stuck in with his team.  He's also been very helpful on the phone when I've called for advice, the latest time being when I locked myself out of the boot by disconnecting the cable release mechanism in order to replace the carpets!


I'm human, just not like the rest! Why? ChromeLotusEsprit.com

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As you can see in that pic, the pulley is already removed. Next get the pump out and finally the bracket, one by one. I tried refitting it first as one big thing and it doesn't even fit through the hole in the chassis hardly, let alone be able to be orientated to the engine. In 3 pieces, it took 30 mins to fit, job done.

 

My bracket snapped, twice by the way. I noticed each time as the water temp rocketed as the water pump stopped too.


88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

Evora NA

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From below, cheers Travis.

 

Cheers Jamie, still a bit way from me then though, but I'll keep them in mind.

 

Bibs, it makes sense now. 30 mins to fit, sounds good. I'll order a pump from the states then. The fragility of the bracket is concerning, any reason for the failures? Pump tensioned too high or poor quality of the bracket perhaps? When the bracket fails, doesn't belt cause havoc in the engine, pump bouncing out the back of the car, or is it still retained some how? Not good either way huh!

 

While I wait for the mechanical pump I've ordered an electric vacuum pump, -18"Hg 12Vdc, about £20 including hose. Not sure if it's up to the job so I'll have the pressure gauge connected too. I think an electric vac pump intended for automotive use would be better (UP28, as mentioned before). I'll have a look at the circuit diagrams to see where I can take my feed from, as there's plenty of wires near the brake servo! I'm wondering if there is a reason to only have the vacuum present when the car is running, will it cause trouble starting etc, but I don't think there is as when you switch off the engine with the mech' pump there is still vacuum retained.

 

I'll let you know how I get on.

 


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Cheers guys, got the vacuum pump out pretty easily using your advice. 

 

My next question is, does the vacuum pump require an outlet? The new unit's outlet appears to be completely blocked off.

 

The image below compares the old pump with a new pump. The new pump is missing the pipe attachment that the old one has fitted, and there was a pipe connected to this that ran to the back of the car, then vented to atmosphere.

 

vacuum_pump_01.jpg

 

To remove this cap meant taking the pump apart which I did (it contains oil inside to lubricate the cam inside, made a right mess!). 

 

What the outlet looks like on the old unit (I've popped it off):

 

vacuum_pump_02.jpg

 

vacuum_pump_04.jpg

 

 

What the outlet looks like on the new unit.

 

vacuum_pump_03.jpg

 

I've had a go at seeing if this is a blanking cap and if it will come off, but it doesn't look like it. I could be wrong and I've just not tried hard enough :).

 

A vacuum pump must have an outlet, no?


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It will have some form of outlet, probably that cap isn't sealed and simply a way of ensuring no debris gets in when running. I'd say leave as it is and just fit that to the existing body and you're good to go.

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Cheers Andy, I'll reattach it to it's other part, which I manage to separate without loosing any of it's oil. I must admit it doesn't look like a vent at all and a strange design but it's hard to see between the rim around it. Perhaps it was a manufacturer modification. As the pump is pretty easy to remove, I'll fit it and see how it performs.

 

If successful, I have another I'll stick up for sale :) . At the cost and shipping from the US, it would be rude not too ;)

 

vacuum_pump_05.jpg


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Learned a few lessons today about that damn vacuum pump, that perhaps I can pass on.

 

When you're replacing your pump, check what's wrong with it. If it's just the diaphragm part then you are in luck, just remove the diaphragm housing from the cam housing part, 4 bolts. Do it with the diaphragm pointing up so the oil from the cam housing doesn't spill.

 

Just swapping diaphragm housings means there is no need to remove the pulley adaptor from the shaft of the cam that's in the cam housing, or more importantly, putting it back on!

 

I learned the hard way by removing the pulley adaptor from the old pump, pretty straight forward (note that I have separated the diaphragm housing from the cam drive in the picture below). 

 

vacuum_pump_06.jpg

 

The problem was putting the pulley adaptor back on on the shaft of the cam. At first I thought I royally b****red up the new pump, as when I pressed it back on, it drove the shaft down in to the back of the housing, meaning the cam was fouling the body. It was grinding a bit. B*****ks. 

 

So moved to the other pump and tried the usual method of freezing the shaft of the pump and heating up the pulley adaptor. First attempt and it fell on, but wasn't quite down far enough. Removed the pulley holder and tried again, and again etc. It just wouldn't go down far enough. I was getting nowhere fast.

 

So I turned my attention back to the pump body that I thought I knackered earlier. I thought, if I can remove the back cap (which the cam was now grinding on) I could use the pullers to pull the pulley adaptor on, and fix the grinding in the process. When I removed the back cap I noticed that a few of the rollers of the roller bearing where now out of the bearing (the cam itself is the roller bearing). So the shaft had to come out to put the rollers back in place.

 

With the roller bearing back together, I pressed the shaft back in to the housing with enough of the shaft protruding out the other end for the pulley adaptor sit as the original did. Finally time to press that damn pulley adaptor on the shaft. It was going so well I stopped to take a pic.

 

vacuum_pump_07.jpg

 

Next all I had to do is press in the cap at the back, with some loctite on the seat inside the housing. 

 

vacuum_pump_08.jpg

 

Then all it needed was topped up with some oil and the diaphragm refitted. What a damn hassle that was, yet interesting!

 

TLTR: Just swap diaphragm housings between your old and new pump, unless you feel the problem is in the cam housing!


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That port is the air outlet.  The replacement that you bought has a different air outlet, as you found, and it works fine, no need to modify, other than transfer the pulley and bracket.  Lotus had that hose on the pump inlet probably to reduce noise, but people who have used that pump, without the outlet pipe, have reported that it isn't any noisier.


Travis

Vulcan Grey 89SE

My Lotus Photo and Projects Album

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Andy, it seemed too simple, and also thought may as well replace the whole pump. It was a good learning experience; some folk crack open gearboxes, I do vacuum pumps ;)

 

Travis, I had sussed out that the holes on the diaphragm housing where blocked off on the original one, and the modified port was outlet with a little mesh gauze present. As a crude method of testing the pump, blocking either inlet and outlet with a hand or finger and turning it by hand results in a significant suck or blow with the new pump. The old pump not so much, so I have high hopes that the new pump will fix my issues.

 

I popped the blanking cap off the old pump to have a look.

 

vacuum_pump_09.jpg

 

vacuum_pump_10.jpg


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Scary business! 

 

I think my brakes will be fookin' marvellous after refurbing all brake callipers (3 of which were seized) and have better vacuum to drive the servo. Not as good as the lads who have upgraded their callipers though, something I'd really like to do.


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As I mentioned in my thread with the brake lights, I've now fitted the vacuum pump and all is well. Vacuum pressure has gone up from 7 inHg to 25 inHG, which is a big jump.

 

vac_test_03.jpg

 

The new vacuum pump is audible, but to what extent I'm not sure as I can only drive it off my driveway and in to the garage. I have noticed a big improvement in the brakes already too.

 

vacuum_pump_11.jpg

 

Cheers to all for the help!

Edited by Mysterae

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Last week I thought the vacuum pump had come loose, as so often before. NO brakes and temp rising. Managed to pull over and stop before over heating.

Got a tow home and prepared to get greasy refitting the screws that secure the pump (and keep belt tension) only to find the bracket broken and that the screws holding it to the engine block
had sheared! I'm not sure I can drill the remains of them out with the engine in place, not much room.

My plan now looks like this:
1. Get an electric pump and fit it.
2. Fit a belt that only drives the water pump.

Need info/part no of both suitable pump and belt. And all the advice I can get on this subject :)


========================================
Torque times RPM equals horsepower!

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@Corban pretty common occurrence in my opinion...  I've seen and heard of that happening many times.

The remaining bolts may not be stuck in the block, they may just be loose now that the bolt head has sheared off...?

Some have switched to an electric pump and an accumulator with a one way check valve.  Then you'd just need a smaller belt to the water pump and a method to adjust tension.

 


Travis

Vulcan Grey 89SE

My Lotus Photo and Projects Album

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Henrik, have a look at the Hella UP 28, 30 and 32 series of electric vacuum pumps.

Or alternatively, as Sparky's in Copenhagen and Malmö, tell him to get those broken bolts out for you while he's not doing anything else.


Margate Exotics.

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Thanks for quick replies :)

The Hella pump looks right for the task, so I need to get some kind of accumulator to store the vacuum? Or could the pump just run continously like the mechanical original does?
I found a belt with part no A907E6296F in "1980-87 turbo parts list", this looks like it will fit tripple pulley to water pump without the VP ( could it be SJ907E0046?).

Sparky! Get over here ASAP! :lol:
The screws that remain are hard to get a grip on, sheared not flush with surface but some distance in... :(
Think they will have to come out the day I pull the engine.

This is my second Esprit and I've had the VP come loose twice on the first one and now three times on the current one. Loctite is a must but it wont prevent bracket failure.
It is really a dangerous design since you practically loose all breaking power. Fortunately I've been in situations of low speed and few other cars around, but if it had been
spirited driving who knows what could have happened. 

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========================================
Torque times RPM equals horsepower!

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Update on the short belt for the water pump. I ordered one from SJ and it IS short... but it will fit when in place.
This is how I did it (it wasn't too hard when I finally mustered the guts).
Slacken belt to alternator.
Crawl under the car and disconnect the belt from crank pulley.
In my case, remove old belt for vacuum and water pump.
Before you crawl under, make sure gear is in neutral.
Fit the new shorter belt over water pump pulley and place as much of it as you can in the center groove of the crank pulley.
Use a 19mm socket with handle and fit to the crank pulley center.
Keep the new belt in its groove with a finger (as much of it as possible) and start turning the engine with the socket wrench. Turn in engine's working direction.
It will be harder and harder to turn and the belt will start slipping, then I used a large screwdriver as a lever in the outer groove to make the belt keep rotating. It will turn inside out but keep turning, it will adjust itself when completely in the groove.

After an hour of trying to fit to crank pulley first, trying to unbolt water pump pulley etc etc this took me less than 5 minutes.

Now I'm planning on how to wire my electric vacuum pump and where to place it, bought the Hella UP28.
 

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========================================
Torque times RPM equals horsepower!

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I'm not done with the complete installation yet. I will try without a seperate accumulator, hoping the volume in the servo is enough. On the Hella home page I found a video of the UP30 and 32 and it didn't look like they were using an extra accumulator. They also seemed to have a "built in" pressure sensor that turned the pump on/off when needed. This, the UP28 is lacking.
My plan is to use the Esprit's "low vacuum" relay, route the ground connection via another relay that starts the pump. I still havn't found the right spot to install the vacuum pump. Would like to have it close to the master cylinder.
I will keep posting as I progress.


========================================
Torque times RPM equals horsepower!

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If you can get one that knows how much vacuum there is, that would be useful, as long as it doesn't suddenly make a racket each time you brake! That would get annoying.

I suppose you could fit it in the front compartment, but then it probably would be noisy.

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