1 hour ago, DaveT70 said:

I know ours have (JLR)

So that's jlr, not all EVs, or even hybrids. Care to show me where the vacuum pump and servo is on this Kuga hybrid

My petrol Mk4 Focus had an electric brake booster...  Horrible pedal feel, but at least it's not going to clog with bits of wetbelt.  

I've got used to the EBB. It can be a bit unnerving when you go to stop at low speed and it eases things for you, I don't think it stops any slower, just eases the jerkiness. It reacts to how quickly you press the pedal.

It means I get in my mum's Kuga and can find the breaks a bit grabby but also not as powerful when I expect them to be.

I do find if you really want maximum breaking performance with EBB in a non emergency situation, i.e. you haven't suddenly hit the brakes but are slowing down from motorway speeds, you do really have to ask for it.

Mache -e 

16 hours ago, alexp999 said:

Regardless of the cause, the engine stopping while driving causing the servo to lose pressure is not the same thing as the engine carrying on running but the vacuum getting blocked. That’s all my point was. I made this clear the conversation moved on. You don’t need to come in to every thread and try stoke things up again with your immovable opinion. 

This is exactly what I was getting at.

Everyone driving these days should know that the brakes lose vacuum assistance when the engine is not running. I would find it highly unlikely that bits of disintegrating wet belt would make it to block the oil supply to the vacuum pump with no other symptoms (oil pressure light etc).

1 hour ago, dontpannic said:

Everyone driving these days should know that the brakes lose vacuum assistance when the engine is not running. I would find it highly unlikely that bits of disintegrating wet belt would make it to block the oil supply to the vacuum pump with no other symptoms (oil pressure light etc).

I haven't checked in FORScan if there are any PID's for lack of Vacuum Boost Pressure and I don't know if there are any Ford specific or Generic Fault Codes either, but I do know that the Vacuum Boost Pressure is monitored in at least two or three ways in my car because I have seen the results of the monitoring in Freeze Frame Data along with other important things that are monitored.

Every time the above mentioned Freeze Frame data was shown it had nothing to do with Brakes or in some cases Engine problems.

Interesting how this thread rolls on, and from reading some of the comments  I would offer a few observations based on my experience with a Mk3 1.0 manual Ecoboom.

It would (in my opinion) be unlikely that the oil pump belt is somehow responsible for oil pump strainer blockage. Viewing the one I've removed shows little sign of deterioration at approx 70k, has a different construction to the OEM cambelt, is substantially smaller by mass than the cambelt which shows substantial degradation.

Although apparently not a common occurrence, I would suggest it could be possible for the vacuum pump strainer gauze to block with the engine still running. I've seen the debris that collects there (and in other components). This type of failure could be exacerbated by people replacing/cleaning oil pumps, replacing belts, but failing to remove and inspect the vacuum pump gauze.

Whilst I don't have a proven example of failure, note that there are two silicone diaphragms in the vacuum pump. One that we're all aware of causing turbo issues, but there is another (almost identical) one that is part of brake servo assistance.

Don't confuse partial vacuum - created by the vacuum pump for the braking system and turbo wastegate operation, with boost pressure in the inlet tract - created by the turbocharger. 

 

36 minutes ago, RayC333 said:

It would (in my opinion) be unlikely that the oil pump belt is somehow responsible for oil pump strainer blockage. Viewing the one I've removed shows little sign of deterioration at approx 70k, has a different construction to the OEM cambelt, is substantially smaller by mass than the cambelt which shows substantial degradation.

Some interesting comments there, Ray. That one in particular might give some comfort to those with revised (chain cam) engines who are still concerned about the oil pump belt. 

 On the vacuum pump, while still trying to find what I'd seen some time back on belt particles, I came across this video which is about vac pump replacement but note the remarks in the first comment which I've copied below

https://m.youtube.com/watch?v=R42QKABwFjw

"I'd just like to say a huge thankyou, today I replaced my own vacume pump, it was rattling and whining due to oil starvation and clogged inlet filter. Causing breaking and turbo issues. I have previously had the wet belt replaced, but obviously belt particles had already wrecked the pump."

3 hours ago, RayC333 said:

Don't confuse partial vacuum - created by the vacuum pump for the braking system and turbo wastegate operation, with boost pressure in the inlet tract - created by the turbocharger. 

I don't know if that comment was in relation to my previous post Ray but I was not, see the Screenshot and my car definitely monitors the Vacuum in the Servo as well as the pre and post Throttle Vacuum/Pressure and if either of them were minus 97kPa I would be in trouble🤣

What about the fuel filter. Does it affect the wet belt?

Because fuel filter never requires to be changed.

13 hours ago, RayC333 said:

Interesting how this thread rolls on, and from reading some of the comments  I would offer a few observations based on my experience with a Mk3 1.0 manual Ecoboom.

It would (in my opinion) be unlikely that the oil pump belt is somehow responsible for oil pump strainer blockage. Viewing the one I've removed shows little sign of deterioration at approx 70k, has a different construction to the OEM cambelt, is substantially smaller by mass than the cambelt which shows substantial degradation.

Although apparently not a common occurrence, I would suggest it could be possible for the vacuum pump strainer gauze to block with the engine still running. I've seen the debris that collects there (and in other components). This type of failure could be exacerbated by people replacing/cleaning oil pumps, replacing belts, but failing to remove and inspect the vacuum pump gauze.

Whilst I don't have a proven example of failure, note that there are two silicone diaphragms in the vacuum pump. One that we're all aware of causing turbo issues, but there is another (almost identical) one that is part of brake servo assistance.

Don't confuse partial vacuum - created by the vacuum pump for the braking system and turbo wastegate operation, with boost pressure in the inlet tract - created by the turbocharger. 

 

When the oil pump belt fails it actually strips teeth

10 minutes ago, DaveT70 said:

When the oil pump belt fails it actually strips teeth

Isn't that for vehicles affected by the US recall, ie autos:

https://www.ford.com/support/how-tos/recall/recalls-and-faqs/23s64-ecosport-and-focus-2016-2022-engine-oil-pump-failure-recall/

US investigation found:

The investigation found that the tensioner's "caulking" (or RTV-like) joint breaks down from vibration over the vehicle's service life, allowing the tensioner arm to fall out of position. It can impact the balance shaft, damaging the tensioner and straining the belt. Ford technicians have also speculated this can lead to the loose belt's teeth skipping over the oil pump sprocket, tearing them off to gather in the oil pan. Either can cause a drop or total loss of oil pressure, both of which can ruin an engine.

One thing that I can't get my head around is if the Teeth fall off then they could easily block the Strainer, fine, but how does that debris get through the Strainer then Oil Filter and block the Vacuum pump Gaze all of a sudden - if that actually happens on its own like some people are claiming.

9 minutes ago, Tizer said:

One thing that I can't get my head around is if the Teeth fall off then they could easily block the Strainer, fine, but how does that debris get through the Strainer then Oil Filter and block the Vacuum pump Gaze all of a sudden - if that actually happens on its own like some people are claiming.

The oil by the outside of the pump is before the strainer so goes around the system

3 hours ago, Bol said:

What about the fuel filter. Does it affect the wet belt?

Because fuel filter never requires to be changed.

?

There isn't a fuel filter as such . Only the gauze filter in the intank pump which every car has

 

Stripdown video (US, so a balancer shaft engine). Passes half an hour while having a cuppa and a biccy and some interesting remarks in the comments. 

https://m.youtube.com/watch?v=0yx1-50iqnA

 

36 minutes ago, DaveT70 said:

The oil by the outside of the pump is before the strainer so goes around the system

The Vacuum Pump is a lot higher than the Oil level and is pumped to the Vacuum Pump via the Strainer so must go through the Oil Filter and Strainer first, hence why I said what I said.

7 minutes ago, Tizer said:

The Vacuum Pump is a lot higher than the Oil level and is pumped to the Vacuum Pump via the Strainer so must go through the Oil Filter and Strainer first, hence why I said what I said.

It will always manage to get anywhere, if it's in the system, after a while

1 minute ago, DaveT70 said:

It will always manage to get anywhere, if it's in the system, after a while

I agree as far as the outside is concerned but people were complaining that the Gauze in the Vacuum Pump  was getting clogged up with Belt debris. The only way it could get to the Gauze is if it was pumped there via the Pump Gauze and Oil Filter.

Just now, Tizer said:

I agree as far as the outside is concerned but people were complaining that the Gauze in the Vacuum Pump  was getting clogged up with Belt debris. The only way it could get to the Gauze is if it was pumped there via the Pump Gauze and Oil Filter.

I'm sure the seal goes on the pumps and oil gets in from the cams

12 minutes ago, Tizer said:

The Vacuum Pump is a lot higher than the Oil level and is pumped to the Vacuum Pump via the Strainer so must go through the Oil Filter and Strainer first, hence why I said what I said.

The oil filter gets bypassed through a relief valve when there's enough of a restriction in it.  Then dirty oil is circulated around the system...

Just now, TomsFocus said:

The oil filter gets bypassed through a relief valve when there's enough of a restriction in it.  Then dirty oil is circulated around the system...

Ah, there you go

30 minutes ago, TomsFocus said:

The oil filter gets bypassed through a relief valve when there's enough of a restriction in it.  Then dirty oil is circulated around the system...

I kind of get why they did that, but seems like a dumb decision in hindsight.

If there was no path other than through the filter, it would trigger the low pressure light BEFORE any debris got sent around the engine.

36 minutes ago, TomsFocus said:

The oil filter gets bypassed through a relief valve when there's enough of a restriction in it.  Then dirty oil is circulated around the system...

I'm out and about just now so can't check but given that these Engines will have either a two stage or muilt stage Solenoid and Duty Cycle controlled Pump,are you sure about that Tom.

43 minutes ago, DaveT70 said:

I'm sure the seal goes on the pumps and oil gets in from the cams

The Oil to the Cams is pumped too.