Brakes: Parking Brake: How hard should peddle be?

[Clan]

Originally Posted by Tannaton

Yeah - I get all that - and I referred to the Highway Code's versions.

But in the real world when did anyone ever get prosecuted specifically for leaving their vehicle in "P" Park and not applying the handbrake?

I bet £10 to the Donkey Sanctuary that the answer to that is never.

I agree it is best practice to use both but on many XC90's the "P" position of the gearbox is far more effective than the parking brake.

Leaving the car in P does not lock the wheels , they are still completely free to rotate , although in opposite directions due to the action of the usual differential gears . So , for example if you park on a steep hill just in P to hold it , which ever wheel has the least resistance to rotate (if there are wet leaves , mud , snow or ice or tiny loose stones under a wheel )you can see you car is free to roll back down the hill with that wheel turning in the opposite direction . The parking brake locks both rear wheels to the chassis so they cannot rotate at all .

[SwissXC90]

Originally Posted by S60D5-185

True but only because the handbrake on the xc90 is inherently crap!

Only when in bad condition
In good condition it works fine

I know, I've had both....

[Tannaton]

Originally Posted by Clan

Leaving the car in P does not lock the wheels , they are still completely free to rotate , although in opposite directions due to the action of the usual differential gears . So , for example if you park on a steep hill just in P to hold it , which ever wheel has the least resistance to rotate (if there are wet leaves , mud , snow or ice or tiny loose stones under a wheel )you can see you car is free to roll back down the hill with that wheel turning in the opposite direction . The parking brake locks both rear wheels to the chassis so they cannot rotate at all .

Quite true... so glad I haven’t got a Land Rover Defender or Discovery 1 or 2 where the parking brake acts on the rear prop shaft... oh sh*t I’ve just seen my signature and I have got one.......... better get a couple of bricks then?

[Father Ted]

Originally Posted by Clan

Leaving the car in P does not lock the wheels , they are still completely free to rotate , although in opposite directions due to the action of the usual differential gears . So , for example if you park on a steep hill just in P to hold it , which ever wheel has the least resistance to rotate (if there are wet leaves , mud , snow or ice or tiny loose stones under a wheel )you can see you car is free to roll back down the hill with that wheel turning in the opposite direction . The parking brake locks both rear wheels to the chassis so they cannot rotate at all .

Yeah, but really; I wonder if this has ever happened?
If the hill is steep enough to worry about that, then I'd be in P, with parking brake on and wheels turned into and resting against kerb (yup, I used to live on a steep hill).

But, talking generally, I need to get to the bottom of why this is happening and the pattern seems to be intense pain after driving the XC for a day or so. I'm going to check my cables and also the adjustment (maybe I've simply tightened it up too much).
In the meantime, I'm sure my common sense will let me know if I NEED to use parking brake, or if P position is sufficient in the specific circumstances I find myself.

And I'll add another tenner to Tannaton's wager. ;-)

[trumpetdropper]

This might be a bit controversial but the fault may not be the parking brake, but could be your seating position? - Personal experience!

My very petite wife drives the XC90 all the time and has no problem with applying the parking brake. Indeed when I get in it after her I can tell she has applied the brake better than I, due to the heavier thump when releasing it.

Whereas, I am a relatively big bloke (20st) with arthritis and struggle to get my knee high enough to set the brake with any decent force but I have got it to hold the car - retrofitting the manual adjusters help!

Notwithstanding the above and why I think it may be seating position is that when I drive the XC90 I suffer from very sore ankles and tendon strain afterwards, this I have discovered is partially due to the way my shoes rest against the back of my heels and it changes depending on the shoes/boots I'm wearing and the pivot point of the heel when applying pressure to the peddles.
When I'm driving a normal car my legs are out in front knees extended heels resting on the floor further away from foot. Whereas, in the XC knees are bent feet are nearly flat on floor so more flex of the foot is required on the peddles or movement of whole leg.

I have also noticed than the left foot rest doesn't suit me in the XC90, so on the motorway/dual carriageway (or wherever I can) I use the cruise control and put my feet flat to the floor and use them as little as possible. I am also looking to fit an accelerator plate (similar to a BMW) on the XC90 instead of the peddle, as I think this might help further.

I sure to some I'm talking complete rubbish, but as I am slave to my feet and leg aliments (hence switching to the XC90, because I struggle to get in/out of some "normal" cars) I'll consider and try anything to keep driving.

[Father Ted]

Thanks.
I've just altered the seat position due to back pain. Believe it or not, I actually Googled correct position. I have the seat a little lower, but further back now and the angle to the Park brake peddle is a lot different. Maybe you've hit the nail on the head.

[WrathOfKain]

Originally Posted by SwissXC90

i measure the following performance on brand new XC90 parking brakes:
0 clicks: car rolls freely
1 click: noticable drag on a flat surface, at idle the D5 is only slowly moving the car forwards or backwards.
2 clicks: easily holds the D5 motor at idle on a flat surface, in D or in R. Holds the car on a slight gradient.
3 clicks: solidly holding the vehicle on a easy to medium gradient
5 clicks: solidy holding the vehicle on a 17% (steep) gradient, pointing uphill, with motor in D (motor is providing some brake assistance)
6 clicks: holding the vehicle solidly on a 17% (steep) gradient, pointing uphill or downhill, with motor running and gearbox in D, R or N.

Here in Switzerland the brake must hold the vehicle on an 18% (1 in 5) hill. That is a very steep hill. It can, if it grips well.

I had my parking brake completely renewed 2 weeks ago.
You likely have rust or worn pads affecting the ability to grip.
At best a disassemble and clean.
At worst renew brake pads, brake disc and springs (this is what I had done)

Read my post describing the parking brake performance, when new, here in page 3 post #29:
https://www.volvoforums.org.uk/showt...=279043&page=3

And then make a cup of tea and read my entire inspection saga starting at page 1 post #1 here:
https://www.volvoforums.org.uk/showthread.php?t=279043

Gonna give this a try tomorrow.

[WrathOfKain]

Originally Posted by S60D5-185

Apart from being illegal that is a real bad idea as it is putting a lot of strain on a small pin in the gearbox for which it was never designed.

I have noticed when i engage the P it moves slightly back when on a gradient so always using the handbrake. Is this movement normal and is there a best practice on this i.e. stop - apply foot on brake - apply G/B P - apply park brake - remove foot brake ?

[Moose Test]

I make it a habit when parking up to:

1) apply foot brake
2) apply parking brake (which is in good condition and holds well)
3) release foot brake
4 apply foot brake again (to unlock gear selector solenoid)
5) engage 'P'
6) release foot brake.

In my mind, this is somehow reducing the strain experienced by the parking pawl, by eliminating all wheel and chassis movement prior to inserting it. Interested to hear opinions on the matter. Like many habits, it may not stand up to logic or scrutiny.

[Tannaton]

Originally Posted by Moose Test

I make it a habit when parking up to:

1) apply foot brake
2) apply parking brake (which is in good condition and holds well)
3) release foot brake
4 apply foot brake again (to unlock gear selector solenoid)
5) engage 'P'
6) release foot brake.

In my mind, this is somehow reducing the strain experienced by the parking pawl, by eliminating all wheel and chassis movement prior to inserting it. Interested to hear opinions on the matter. Like many habits, it may not stand up to logic or scrutiny.

I think the above falls into the category of "good mechanical sympathy".