Brakes problem, lots of parts changed

kontad · Post by **kontad** » 17 Jul 2024, 07:23

Hello guys,

My name is Juan, I´m from spain and I´m the proud owner of a 2003 Volvo s60 2.4 170hp

Since I bought it in febreary 2023, the car has problem with the brakes. When I push the brakes, at the very beginning of the brake travel the car brakes ok, but in the middle of the brake travel it dont brakes at all, till you almost push the pedal to the bottom, where the car brakes ok.

My mechanic has changed the brake pump vacuum, the booster vacuum switch, the servo and the brake master cylinder, but the problem is still there.

Im thinking now of the ABS module but I have no error codes...

Anyone please can help me? I have no idea at all about what can be and I have read almost every post about brakes problems

Post by **jonesg** » 17 Jul 2024, 08:01

it might be air in the abs system, it requires cycling the abs valves as the calipers are being bled.
vida or a good scanner tool is required to do this.
once the air is pushed out of the abd valves the calipers have to be bled at each wheel to remove the air from the system.

kontad · Post by **kontad** » 17 Jul 2024, 08:16

So maybe I have to go to the dealer of find a mechanic with a volvo scanner

Its so strange cause If I brake twice fast, the first brake is as I described in the post, but in the second brake the pedal has a lot more of "pressure" and it almost feels like there is no problem in the brakes. Then 4-5 seconds past and the brakes are dead again in the middle of the brake pedal travel

jonesg wrote: ↑17 Jul 2024, 08:01 it might be air in the abs system, it requires cycling the abs valves as the calipers are being bled.
vida or a good scanner tool is required to do this.
once the air is pushed out of the abd valves the calipers have to be bled at each wheel to remove the air from the system.

Post by **jonesg** » 17 Jul 2024, 10:15

that sounds like air in the system.
if you go to the dealer it will be very expensive. Don't do it.
was the system bled ?

kontad · Post by **kontad** » 17 Jul 2024, 13:00

Yes, they bled the brakes several times when they changed the servo and the master cylinder, they made the bled in the correct order, but as far as I know, they did not use any scanner tool.

Thank you very much for your help sir

jonesg wrote: ↑17 Jul 2024, 10:15 that sounds like air in the system.
if you go to the dealer it will be very expensive. Don't do it.
was the system bled ?

Oro · Post by **Oro** » 17 Jul 2024, 14:04

I have an iCarSoft Volvo scanner that has an ABS bleed feature in the software - this is what Vida does. A cheap/knock-off laptop/Vida scanner may be cheaper, but there are non-Vida options, too.

There is a shade-tree mechanic hack for this. I used it once on a FWD Chevy Aveo (IMO, the crappiest car sold in the USA (so far) this century…) with success. With the drive axles lifted free of the ground, car idling and in D, grab one wheel and stop it. It will trigger the ABS to fire and self-bleed. The Aveo was small and FWD and this actually worked. The front wheels weren’t turning very quickly in this scenario, I wore leather work gloves, and it did the trick. *Might* work for you if you can’t get a software bleeder/trigger device.

If you have dirt/gravel roads nearby you can go try to activate the ABS system the old fashioned-way, too.

Post by **MoVolvos** » 17 Jul 2024, 18:05

.
Your mechanic needs to do a complete flush of the system all at one time. I started using this method for a full flush so the person in the car doesn't have to continually pump 3 times and hold. Start the car and just have the person in the car push the pedal and hold allowing the ABS to move the brake fluid. I then release the bleeder screw with a clear hose attached and into a bottle. The hose end is submersed in some brake fluid in the bottle to keep air from back siphoning / flowing. I will open and close the bleeder screw till new fluid comes out as bleeding maybe not get all the air in the line since the system was opened.
.

Post by **jonesg** » 18 Jul 2024, 08:48

kontad wrote: ↑17 Jul 2024, 13:00 Yes, they bled the brakes several times when they changed the servo and the master cylinder, they made the bled in the correct order, but as far as I know, they did not use any scanner tool.

did they bench bleed the master cylinder before installing ??

kontad · Post by **kontad** » 18 Jul 2024, 11:51

I don´t really know... the mechanic had been trying to repair the brakes for more than 1 month, but the brakes are exactly the same so I think I will test the ABS like you Oro told me and then search for another mechanic...

jonesg wrote: ↑18 Jul 2024, 08:48
did they bench bleed the master cylinder before installing ??

Post by **firstv70volvo** » 18 Jul 2024, 12:26

kontad wrote: ↑17 Jul 2024, 08:16 So maybe I have to go to the dealer of find a mechanic with a volvo scanner

Its so strange cause If I brake twice fast, the first brake is as I described in the post, but in the second brake the pedal has a lot more of "pressure" and it almost feels like there is no problem in the brakes. Then 4-5 seconds past and the brakes are dead again in the middle of the brake pedal travel

jonesg wrote: ↑17 Jul 2024, 08:01 it might be air in the abs system, it requires cycling the abs valves as the calipers are being bled.
vida or a good scanner tool is required to do this.
once the air is pushed out of the abd valves the calipers have to be bled at each wheel to remove the air from the system.

Worth checking, the correct install of the front caliper springs