2007 xc70 So what would cause brakes to be down to the floor? They say my brakes are fine, Now

Iluvvolvos · Post by **Iluvvolvos** » 03 Aug 2022, 04:17

The poor they’ve ordered from my brakes because my brakes are down to the floor is a master cylinder, but last time they said that the master cylinder was fine and ie brakes for doing the exact same thing

Post by **abscate** » 03 Aug 2022, 04:59

If the fluid is disappearing it is going somewhere. They can leak into the brake booster unseen but a new master cylinder would fix that

Puzzled

Post by **volvolugnut** » 03 Aug 2022, 14:21

For the brake petal to go to the floor when you step on it, a few things must have happened:

1. There is no fluid in the brake fluid tank. Check the level on the outside or remove the cap to see the level.

2. There is a large leak at the master cylinder and the fluid is not getting pushed to the wheels. A leak at the master cylinder may be under the dash on under the hood at the master cylinder.

3. There is a large leak at one of the wheels. You should be able to see a wet area on the inside of the wheel.

4. There may be a leak in one of the brake lines. This is unlikely unless a brake hose is leaking or a brake tube has been damaged by impact.

If you find there is no brake fluid, you must find the leak and repair it. Just adding more fluid is not safe. It will leak out again and you will not have brakes.

volvolugnut

Post by **br0dy519** » 03 Aug 2022, 17:54

vtl has mentioned dealer required to bleed air from ABS. Is that something we can do from vida? Curious about that.

Post by **vtl** » 04 Aug 2022, 09:04

br0dy519 wrote: ↑03 Aug 2022, 17:54 vtl has mentioned dealer required to bleed air from ABS. Is that something we can do from vida? Curious about that.

Absolutely. Trigger inlet/outlet valves of the line you're bleeding with Mityvac or vacuum pistol.

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Well, pumping a pedal may actually work as well. I just was doing it with a pistol, saw a few huge bubbles escaping from one corner. Squishy brakes were bothering me for years in that car. Not a single problem with the brakes linearity after bleeding the ABS.

Post by **scot850** » 04 Aug 2022, 17:31

Your brake pump has failed.

Neil.

Post by **vtl** » 05 Aug 2022, 06:54

scot850 wrote: ↑04 Aug 2022, 17:31 Your brake pump has failed.

Neil.

Why? With no engine boost, the brake booster still gets vacuum from intake manifold. Under boost the brake booster has enough vacuum capacity for 2-3 brakes. When it runs out of vacuum, the pedal becomes very hard.

Post by **br0dy519** » 05 Aug 2022, 09:55

I ran a car without the brake booster pump for 3 years before I realized it had failed. So yes, agree with vtl. Most Likely a hydraulics fluid issue here.

Post by **jonesg** » 05 Aug 2022, 12:47

I had a Ford truck with same problem.
There was a big air pocket trapped in the master cyl.
I pulled it off and bled it on the table.
People have success using a turkey batter and small tube.
A big truck mechanic told me he just sucked it out with a straw and spit it out.

Post by **June** » 05 Aug 2022, 14:03

When you say "goes to floor" do you mean no brakes, petal goes to the floor without resistance? If a long petal travel before braking actually happens, than this is normal for P2 of that Era. My 04 S80 brakes are completely Volvo, only serviced by Volvo dealership. if I push hard enough while at a light it can come so close to the floor I cannot push the other foot toes under the petal. Higher models like my T6 and likely your XC are equipped with EBA (Emergency Brake Assist). During a panic stop It measures the speed you push the petal to determine a panic stop is in progress. This requires petal travel for the position sensor to operate. June