Vacuum pump

[Corban 50]

here is link to the page with the video

http://www.hella.com/microsite-electronics/en/UP28-vacuum-pumps-116.html

[Chillidoggy 4,389]

According to the Hella website, their 30/32 pumps don't need any other assistance from another source which makes them very attractive as a brake vacuum pump, and it doesn't mention accumulator requirements, either. It might be worth contacting .Hella technical to find out. I'm certainly very interested in using a UP32 if I decide to ditch the Delco.

" The UP30/UP32 is installed in the pneumatic section of the brake system, just like the UP28. Both vacuum pumps are ideal for vehicles without any vacuum, such as hybrid/fuel cell, electric or diesel engines."

[Glyn Harper 55]

I can't remember, but does the Esprit provide a bit of vacuum to the brakes with a one way valve, or is that a different circuit just for heater controls, etc?

I seem to remember having a faulty one way valve once but that could very well have been on my old Escort RS turbo!

[Corban 50]

Status update.

Yesterday I was done thinking and planning and the decision was made to mount the pump close to the master brake cylinder.
I put a screw in the hose where the old pump was connected to seal it off.
Inserted a "T-piece" in the section of hose that is closest to the brake servo and connected the pump to that.
I ran the pump with a separate 12V battery to test and I could see the flap to the ventilation outdoor air intake open.
Started the engine and noticed that the brake warning light went out as normal. (looking good so far!)
Drove the car in my yard and checked the brakes, they worked and felt like normal.
Stopped the new pump and imediately the brake warning light came on, so either the vacuum reserve in the brake servo isn't big enough or I have a leak in the system (probably in the ventilation controls as the flap started to close right away).
Started the pump again and after roughly one minute the "check engine" light came on. It did not come on earlier when I started and let the engine run to see if the new belt to the water pump worked. Then I ran the engine for 15 minutes but without the vacuum pump running.
This rings a bell. I've seen this during earlier surgery but can't remember what I did at the time. It could have been removal of the EBPV or the throttle vacuum thingy OR it could have been when I connected the electric chargecooler pump via the relay for the EBPV.  I think it is an easy fix when I figure it out, any suggestions?

 

[Chillidoggy 4,389]

Plug in and Freescan or Espritmon it first to see what the CEL light was all about. Then try blocking off the vacuum line, run it up, and see what happens.

Also, I wasn't aware there's any warning of low vacuum, is there something in the electrics/electronics that registers that, or is it excess master cylinder travel actuating a warning switch in the cylinder body?

[Corban 50]

There is a sensor attached to the brake servo and it turns on the main brake warning light, so it is the same signal as when you apply hand brake.
Was planning to use that signal to trigger a relay to the pump (there is a T-piece on the hose just below the servo with a small hose to the sensor).

Check engine light didn't come on when I tested it today but the pump runs hot when in continous use. I will have to source a vacuum tank, a one-way valve and a pressure relay
to complete the installation and make it reliable.

[andydclements 788]

On 07/08/2017 at 19:57, Glyn Harper said:

I can't remember, but does the Esprit provide a bit of vacuum to the brakes with a one way valve, or is that a different circuit just for heater controls, etc?

I seem to remember having a faulty one way valve once but that could very well have been on my old Escort RS turbo!

Earlier cars had one-way valves , but those were not required once they went to pumps. However, it is a good way to bolster the effect of the electric pump. That could be a very good idea: revert to manifold provided vacuum, with an electric pump to assist at moments when the manifold isn't providing any (when the carbs/ TB flaps are open).

[Chillidoggy 4,389]

1 hour ago, Corban said:

There is a sensor attached to the brake servo and it turns on the main brake warning light, so it is the same signal as when you apply hand brake.
Was planning to use that signal to trigger a relay to the pump (there is a T-piece on the hose just below the servo with a small hose to the sensor).

Check engine light didn't come on when I tested it today but the pump runs hot when in continous use. I will have to source a vacuum tank, a one-way valve and a pressure relay
to complete the installation and make it reliable.

 

What triggers the sensor? Is it a vacuum switch, or a mechanical one? I don't recall ever having seen a switch on a servo before.

[Corban 50]

Think it's mechanical, pos 105 is called "switch, low vacuum warning"

 

[andydclements 788]

You'd not want the pump to be switched by the warning light switch. The pump would only ever (at best) achieve the least pressure difference required to switch the warning light off. You'd really want the pump to:

1) Achieve at worst a pressure difference to turn the warning light off

2) Have hysteresis, turning on at one pressure differential, but turning off at a greater pressure differential. So minimising short runs/ single cycles of the pump.

3) Be operated by a different circuit / sensor to that of the warning system, so as to prevent a single point of failure common to both brakes and warning for brakes.

[Chillidoggy 4,389]

44 minutes ago, Corban said:

Think it's mechanical, pos 105 is called "switch, low vacuum warning"

 

I reckon that is a vacuum switch.

 

I would have thought that the UP28 would provide enough vacuum for the brake servo, but perhaps not when it's connected to other systems which may be leaking. I suspect that's the reason the warning lamp illuminated when you switched the pump off - vacuum had leaked out via the T-piece connection to the heater valves.

Next step I would take is to just have the UP28 connected to the brake servo system, and have another go. If that proves satisfactory, and you have servo vacuum without warning lamps, you could put a one-way valve into the T-piece to prevent loss of vacuum to the servo. I would be wary of using brake servo vacuum to power any other system, but that's a personal choice.

If the UP28 is not enough, there's a UP32 available, but an accumulator could also be used, there are probably a few on the market.

[Corban 50]

Now I've fitted a non return valve between pump and servo, works fine. No warning light comes on when pump turned off.
I can do three full moves with the brake pedal before light comes on.

Andy, I think you are right. Pump will only reach enough vacuum to turn out light. There will be no extra vacuum stored and the light will constantly turn on and off.

[Chillidoggy 4,389]

That's good news.

So now you have the choice of an accumulator, and/or a vacuum line from the inlet manifold.

[MrDangerUS 129]

What is the typical vacuum reading in [inHg] of the Esprit stock mechanical pump? On N/A cars, where vacuum supply hose is attached to the intake manifold, the typical IM vacuum is 17-21 inHG

Isn't it true, that one can regulate the brakes effectiveness (the "grab") by adjusting the vac switch on the pump?

[Loren Stump 1]

I mounted mine next to the front bulkhead fusebox, its actuated by a small adjustable vacuum switch. Runs to a vacuum reservoir. Only needs to activate momentarily to keep the tank pressurized. Works a treat.

[Loren Stump 1]

Here's a picture of my layout.

[Corban 50]

That is a nice solution.  

I rewired my installation yesterday. I let the brake warning light signal (low vacuum) trigger a timer circuit with adjustable time setting. Right now it is set at a 10 sec running time which
seem to be enough to generate sufficient vacuum in the system. I can now do four depressions of the brake pedal before the pump starts again.
Next step is to find a tank/reservoir in order to increase the volume of the system.

[Chillidoggy 4,389]

By way of a comparison, how many pedal depressions did you get with the old system before the hydraulic pump cut in?

[Corban 50]

The old vacuum pump was belt driven on the same belt as the water pump, so it was always running.

I think this changed when they introduced power assisted steering. That pump replaced the vacuum pump.

[Chillidoggy 4,389]

OK, I remember now.

The information I found about the Hella UP28 is that it operates in addition to another vacuum source. The UP30/32 on the other hand is a full stand-alone unit, not requiring any other vacuum assistance.

http://evwest.com/support/SC-VP-Hella-UP28-Vacuum-Pump-Technical-Information.pdf

If and when I ditch the Delco it will be the UP32 I use, as I don't really want to fit an accumulator unless it's necessary.

 

[Corban 50]

@Loren Stump I really like your installation. Do you have the name/type of the vacuum sensor you are using?

[Loren Stump 1]

This isn’t exactly the switch I used but similar. Installed this system a few years ago.

https://m.ebay.com/itm/Adjustable-Vacuum-Switch-Kit-700R4-200-4R-350C-Trans-6-22-Superior-K058-99412-/190780081919

I removed not only the vacuum pump but also the water pump. I replaced it with Davies Craig electric pump.

[MrDangerUS 129]

Here is mine.

[Corban 50]

Two neat installations. I notice you stil have the spare wheel John and managed to squeeze pump and reservoir in.
Loren, looking at your engine I notice a trigger wheel on the belt pulley. So you have upgraded the engine management system? Let's add up some mods, electric water pump, electric
vacuum pump and no AC. Those things alone should free up some horsepower, my guess is somewhere between 10-15 only from doing that.

[Loren Stump 1]

These numbers vary greatly from application to application/vehicle to vehicle and are from various sources.

• Tensioner: ~0 kW 
• Actually some resistance (negligible) 
•  
• AC: 4 bhp
• Many numbers much higher (especially on demand)
•  
• Alternator: 5-6kW (7-10bhp)
• 1.9 torque
• 10 bhp full load
•  
• Water Pump: 10kW (13hp) Davies Craig number.
• 6.2 to 6.4 torque
• 1.1 bhp at 2000rpm, 8.6 bhp at 4000.
•  
• Power Steering: 2-4kW 
• 6.8 to 8.3 in torque
• 2 to 4 bhp
•  
• Vacuum pump: 3-5kW 
• 5.8 to 6.5 in torque
• 3 to 5.2 bhp.
•  
• Resulting in a loss of between 16 and 27bhp and of course weight is another consideration. 
• The following numbers are after subtracting the replacement part weight.
•  
• Water pump  at 6lbs (2.72kg)
• Vacuum pump at 5lbs (2.17kg)
• Tensioners at 2lbs (.9kg)
• Brackets and bolts 3.5lbs (1.59kg)
• Pulley and belts at 2lbs (.9kg)
• Air conditioning at 51lbs (23.18kg)
• Total of 66.5lbs (28.91kg)
• 1hp per 10lbs.or 6.65bhp gain or the feel of it. 
•