Vacuum Pump

[Mark Simpson]

Hello, I'm new to the forum and to Esprit ownership, but I'm learning fast. I'm sure that this topic has been covered, so any pointers to previous discussions would be appreciated.

My 89SE has no brakes, at least no servo assisted brake and no functioning heater control, the combination of these two makes me think it is the vacuum pump at fault. Taking off the suction feed at the back of the servo ( no hiss on removal), shows there is some suction, but it feels weak and pulsing not enough to hold my finger on the pipe,  and does not seem improve much with higher revs. I cannot detect any odd sound that I have read is associated with pump failure

My question is, before I jump into replacing the pump, could it be anything else?  is there a categorical test that will show it's the pump it's self at fault. I do not have a flow or suction meter, if there is such a thing.

Thanks

[Bibs]

Welcome to TLF. Does the pump sound like a duck? That's a sign it's on the way out. If not, there's more than likely a leak somewhere in the vacuum system. You'll have a map on the underside of the tailgate. While there's a solid chance it's a heater valve hose popped off, you can use this diagram to check the vacuum connections starting from closest to the pump and working your way along.

[Mark Simpson]

After testing the suction directly at the pump I decided it was not working as it should be. So I've taken it off and picked up a replacement from Lotusbits, which is a slightly different design, without a distinct exhaust outlet, seems it exhausts through vents in the casing, not sure this is a good thing given the vulnerability of the pumps location. Comparing pumps shows mine was barely working. I  will be fitting it  later today and hopefully brakes and heater controls will be back up returned. I will also trace the vacuum pipes to ensure everything is connected. I'm going to tackle replacing handbrake cables which are in a poor state, down to the steel coil in parts, stiff and no doubt rusty inside side not releasing properly on the drivers side making the caliper bind. Should keep me busy.  

[Vulcan Grey]

that's normal, one version of the pump had the external exhaust64-1005 IIRC, and the other had an internal air exhaust 64-1006 IIRC. They both work fine, and should not be noisy.  

 

64-1006 no exhaust

 

64-1005 exhaust pipe

 

[naasaa]

Do anyone know why Lotus went with the vacuum pump solution?

My 1982 vacuum is from the intake manifold, whereas the 1984 has a vacuum pump fitted.

 

Lars

[Escape]

The vacuum pump is fitted to turbocharged engines. The pressure from the turbo means the manifold can't supply the vacuum (except at idle).

[Mark Simpson]

Changed the pump yesterday. Straightforward, but fiddly. Traced all my vacuum pipes and checked they were all connected.  I now have proper brakes and heater controls  !

I did consider an electric vacuum pump system on offer from Simtek but decided to stick with a conventional pump.

http://www.simtekuk.co.uk/index.php/mobile-vacuum_pump_kits/?k=3232:23

Found my car lift a real benefit, I thought it would prove a good investment.

[andydclements]

I'd bet you thought long and hard about the electric version when you were trying to get the bolts good and tight, PITA of a job.

[naasaa]

My 1982 Turbo has no pump fitted. And this is from factory.

Same,smae with my old Volvo turbo.

The Esprit has a vacuum canister on top of the right hand fuel tank and a check valve. I never experienced lack of turbo for the brakes.

Hence I wonder why Lotus went to this mechanical pump.

[Htown]

Electric pump from the supercharged Range Rover Sport now up front, and have converted to a two v-belt system with no a/c.  So much room for activities!   This should make the Alunox install a breeze, since the new motor will be stabbed before is shows up.    stupid vacuum pumps...  I've had mine fall off completely more than once.

Craig

[naasaa]

Hi Craig

Is this electric vacuum pump an intergrated unit, that controls the vacuum to a specific value?

I have this 1984 which will undergo a substantiel amount of work. One of them is to get rid of some of all those belts. A/C, smog pump and vacuum pump. So, looking into alternative solutions.

Lars

[Htown]

Hi Lars,

It's just a Hella UP28, but packaged in a nice bracket, and I was able to scavenge the required section of vacuum tube at the same time to make install easier on the brain.

You can see the UP28's specs here...   http://hellahd.com/index.php/default/electrics/universal-electric-vacuum-pumps/electrics-product-11/

Some folks may also recommend the UP30 

Craig

[Chillidoggy]

2 hours ago, Htown said:

Hi Lars,

It's just a Hella UP28, but packaged in a nice bracket, and I was able to scavenge the required section of vacuum tube at the same time to make install easier on the brain.

You can see the UP28's specs here...   http://hellahd.com/index.php/default/electrics/universal-electric-vacuum-pumps/electrics-product-11/

Some folks may also recommend the UP30 

Craig

 

Have you felt any need for an accumulator, or are you just running with the vacuum from the Hella?

[davevr6car]

I used an accumulator from an Audi A6, it looks like 3 blue spheres stuck together. I removed the AC pump and fitted the earlier vacuum pump in its place on a custom made bracket....All works just fine..... proper vacuum power and if the engine dies or stalls ....I still have a reserve of vacuum in the accumulator to continue braking.

[Htown]

2 hours ago, ian29gte said:

 

Have you felt any need for an accumulator, or are you just running with the vacuum from the Hella?

I grabbed the accumulator off a Series II Discovery secondary air injection system for good measure.

[Chillidoggy]

12 hours ago, davevr6car said:

I used an accumulator from an Audi A6, it looks like 3 blue spheres stuck together. I removed the AC pump and fitted the earlier vacuum pump in its place on a custom made bracket....All works just fine..... proper vacuum power and if the engine dies or stalls ....I still have a reserve of vacuum in the accumulator to continue braking.

 

How did you deal with the removal or disconnection of the Delco and ABS system ?

[naasaa]

Def something that I have to do.

I see that this Hella pump requires an external control.

Did you connected to a sort of switch?

[Htown]

Yes, ssbc makes one available from summit racing, but requires a relay for switched ground

[davevr6car]

Ian,

I removed the entire Delco ABS system except for the abs computer. Nissan Patrol servo, new SE vacuum pump located where my AC pump used to be.

[Paul93Lotus]

Craig/David,

Couple of questions for both of you since you've been through the conversions...

I've been acquiring the parts for this similar switchover, but with Esprit V8 components and in hope of integrating the KH 430 (pedal box, harness, kh430 valve assembly,booster and master cyl., audi vacuum reservoir, stock brake lines - I may be retrofitting obsolete components but want to retain abs if i can).  What did either of you find as the optimum vacuum switch on/off points to get good brake pedal feel/assist and the least amount of cycling?  I know some of this depends upon the size of booster...

Craig - did you mount the Hella up front? is the pump quieter than the Powermaster hydraulic pump? Can you hear it cycling and is it more or less often than 4-5 brake pushes of the old powermaster? I find the powermaster irritating hearing it come on off - was wondering if hella is considerably quieter.

 

Thanks 

Paul

[sanj]

Inspired by Craig's vacuum pump delete idler shown in his post above (Htown), I designed and had fabricated a similar adjustment plate that uses the existing vacuum pump bracket. Like his, it is designed to use the A/C tensioner pulley, but can alternatively use an off-the shelf idler assembly from a Ford (with the substitution of a different spacer and bolt). Tension adjustment is performed exactly as it is with the factory pump installed, except one can now easily access the top pivot bolt! If anyone else wants to do this I did have a few extras made, PM me for details.

[MrDangerUS]

Volvo XC70 or XC90 electric vac pump can be plumbed into existing vac line by the brake booster.

I added an auxiliary chrome vacuum accumulator tank and FESTO switch to operate the pump. All parts obtained from eBay or Amazon.com.

[sgrobler]

On 06/07/2016 at 03:51, Vulcan Grey said:

that's normal, one version of the pump had the external exhaust64-1005 IIRC, and the other had an internal air exhaust 64-1006 IIRC. They both work fine, and should not be noisy. 

Hi Travis  - the NAPA pumps that you mention don't come with the pulley - how does the pulley get fitted? Is is a press fit that I'll need a press or some heat to get teh old one off and re-fit?

regards

Steve

[Vulcan Grey]

You do have to use a pulley puller to remove the pulley hub from your old pump.  Sorry can't find a photo.

Then you heat the pulley hub in the oven and draw it onto the shaft to the same depth as it was before.  You can use a bolt, holding the pulley hub in a vise.