1999 V70 10v brakes not assisted

SteveSarre · Jan 24th, 2021, 20:14

Hi all,

Can anyone give me some quick guesses what might be wrong with 1999 V70 10v that I bought for parts.

I am just going through it to see what parts are good or bad.

I have to press very hard on the brakes. Feels like they are not servo assisted.
ABS light is on when I turn the ignition on, and goes off shortly after I start the engine. ABS kicks in with a buzz as normal if I brake hard (but I have to press the pedal very very hard).

Car starts and runs OK (so no major vacuum leak as far as I know).

Looks like it has had fairly recent front and rear calipers and hoses.

Thinking a bit more I have had the idle air control valve off to clean it, and put it back together without the 3 clamps. Could that be affecting the brake servo assist but not affecting starting and running?

Thanks
Steve

ITSv40 · Jan 24th, 2021, 21:01

An easy way to test the servo is:

Without starting the engine press the brake pedal until it becomes firm - probably about a third of the travel to the floor. Then keeping your foot on the pedal start the engine and let it run. Immediately on starting the engine the pedal should fall under the pressure of your foot and become firm again at about two thirds travel. Once it has become firm with the engine running it should hold the firmness. If this doesn't happen the servo is not operating, if it does you need to look elsewhere.

Bob Meadows · Jan 24th, 2021, 21:13

Worth checking the servo valve - connections & hose line.
Bob.

400-ascona · Jan 25th, 2021, 08:47

Quote:

Originally Posted by SteveSarre

Hi all,

Can anyone give me some quick guesses what might be wrong with 1999 V70 10v that I bought for parts.

I am just going through it to see what parts are good or bad.

I have to press very hard on the brakes. Feels like they are not servo assisted.
ABS light is on when I turn the ignition on, and goes off shortly after I start the engine. ABS kicks in with a buzz as normal if I brake hard (but I have to press the pedal very very hard).

Car starts and runs OK (so no major vacuum leak as far as I know).

Looks like it has had fairly recent front and rear calipers and hoses.

Thinking a bit more I have had the idle air control valve off to clean it, and put it back together without the 3 clamps. Could that be affecting the brake servo assist but not affecting starting and running?

Thanks
Steve

Good advice.

400-ascona · Jan 25th, 2021, 08:48

ITSV40 - Good advice.

SteveSarre · Jan 26th, 2021, 18:16

Hi all

Thanks to ITSv40 for his suggestion.

Engine off, press brake pedal down. It firms up after 30% down.
Keep pressing, engine on, no further movement down.
ie no vacuum assist.

I will briefly check that a vacuum is present in the hose at the servo end, but other than that, I probably wont try to fix it because I just bought this car for parts.

Thanks,
Steve

SteveSarre · Feb 4th, 2021, 13:09

Hi all

Vacuum is present in the hose at the servo end, so I will probably leave it at that, since this car is for parts only.

Thanks,
Steve

Luxobarge · Feb 4th, 2021, 14:01

Sounds like servo diaphragm has gone.

Jan 24th, 2021, 20:14	#1
SteveSarre Premier Member Last Online: Yesterday 15:16 Join Date: Oct 2004 Location: London/West Country	1999 V70 10v brakes not assisted Hi all, Can anyone give me some quick guesses what might be wrong with 1999 V70 10v that I bought for parts. I am just going through it to see what parts are good or bad. I have to press very hard on the brakes. Feels like they are not servo assisted. ABS light is on when I turn the ignition on, and goes off shortly after I start the engine. ABS kicks in with a buzz as normal if I brake hard (but I have to press the pedal very very hard). Car starts and runs OK (so no major vacuum leak as far as I know). Looks like it has had fairly recent front and rear calipers and hoses. Thinking a bit more I have had the idle air control valve off to clean it, and put it back together without the 3 clamps. Could that be affecting the brake servo assist but not affecting starting and running? Thanks Steve __________________ V70 2.5 Turbo AWD Man. 1999 Red V70 2.5 10V Auto 1998 Green C70 T 20V Auto Conv. 2001 Blue, C70 T5 Auto Conv. 2000 Blue V70 2.5 Turbo AWD Auto 1998 Green, V70 2.5 10V Auto BiFuel 1999 Red (scrapped) V70 20v Auto 1999 Green (scrapped)

Jan 24th, 2021, 21:01	#2
ITSv40 VOC Member Last Online: Today 14:28 Join Date: Mar 2008 Location: Northampton	An easy way to test the servo is: Without starting the engine press the brake pedal until it becomes firm - probably about a third of the travel to the floor. Then keeping your foot on the pedal start the engine and let it run. Immediately on starting the engine the pedal should fall under the pressure of your foot and become firm again at about two thirds travel. Once it has become firm with the engine running it should hold the firmness. If this doesn't happen the servo is not operating, if it does you need to look elsewhere. __________________ 2001 V40 2.0lt Sport lux - Daily Driver. 174k miles. 2003 C70 2.4 GT Convertible - Garage Queen. 65k miles. http://www.neptuno6benagil.com

Jan 25th, 2021, 08:48	#5
400-ascona Premier Member Last Online: Apr 19th, 2024 10:05 Join Date: Mar 2008 Location: Derby	ITSV40 - Good advice. __________________ 1997 V70R AWD, Saffron, Manual; Lotus Carlton; Ascona 400; Mini Cooper S Works; 4.2 Supercharged Range Rover; Land Rover Discovery 4; Suzuki GSF1200N; BMW R80/7; Velocette Venom; Daimler V8 250.

Jan 26th, 2021, 18:16	#6
SteveSarre Premier Member Last Online: Yesterday 15:16 Join Date: Oct 2004 Location: London/West Country	Hi all Thanks to ITSv40 for his suggestion. Engine off, press brake pedal down. It firms up after 30% down. Keep pressing, engine on, no further movement down. ie no vacuum assist. I will briefly check that a vacuum is present in the hose at the servo end, but other than that, I probably wont try to fix it because I just bought this car for parts. Thanks, Steve __________________ V70 2.5 Turbo AWD Man. 1999 Red V70 2.5 10V Auto 1998 Green C70 T 20V Auto Conv. 2001 Blue, C70 T5 Auto Conv. 2000 Blue V70 2.5 Turbo AWD Auto 1998 Green, V70 2.5 10V Auto BiFuel 1999 Red (scrapped) V70 20v Auto 1999 Green (scrapped)

Feb 4th, 2021, 13:09	#7
SteveSarre Premier Member Last Online: Yesterday 15:16 Join Date: Oct 2004 Location: London/West Country	Hi all Vacuum is present in the hose at the servo end, so I will probably leave it at that, since this car is for parts only. Thanks, Steve __________________ V70 2.5 Turbo AWD Man. 1999 Red V70 2.5 10V Auto 1998 Green C70 T 20V Auto Conv. 2001 Blue, C70 T5 Auto Conv. 2000 Blue V70 2.5 Turbo AWD Auto 1998 Green, V70 2.5 10V Auto BiFuel 1999 Red (scrapped) V70 20v Auto 1999 Green (scrapped)

Jan 24th, 2021, 21:13	#3
Bob Meadows Premier Member Last Online: Today 12:17 Join Date: Sep 2017 Location: STANDISH LANCASHIRE	Worth checking the servo valve - connections & hose line. Bob.

Feb 4th, 2021, 14:01	#8
Luxobarge Premier Member Last Online: Today 14:11 Join Date: Jan 2011 Location: Horne (Nr. Horley)	Sounds like servo diaphragm has gone. __________________ Some people are like Slinkies, they serve no useful purpose but they still bring a smile to your face when you push them downstairs.

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