跳转到主内容

The 5th generation BMW 3 Series is based on the E9X platform. The car pictured is a E90 chassis. The E9X chassis was used from 2004-2013 when the F1X chassis was released. When talking about a non-specific chassis, this generation is typically referred to as the E9X chassis since there are multiple chassis for this generation of 3 series, depending on the body style (E90/E91/E92/E93).

28 个问题 查看全部

Brake Pedal becomes rock hard sometimes.

2010 BMW 320i

Following recent replacement of Rocker Cover and Gasket by BMW, the Brake Pedal sometimes becomes rock hard after the engine is not working for a number of hours. What is the problem?

已回答! 显示答案 我也有这个问题

这是一个好问题吗?

得分 4
1条评论

Vaccum pump is new. But de break is hard

完成的

添加一条评论

5个答案

已选择的解决方案

Hi,

Check if the vacuum brake pump is connected properly or is even working

Park the car and turn off the engine.

Pump the brake pedal five or six times

Start the engine, and keep your foot pushing down on the pedal. Check what happens to the pedal.

With the engine running, the engine sucks the air out of the brake booster, restoring the vacuum. Normally, the pedal will drop towards the floor with your foot applying light and steady pressure on it.

If the pedal pushes back against your foot, then there is a problem. This could be a blocked vacuum hose, a leak in the vacuum hose, or a leak in the brake booster check valve.

Given that it happens after the engine has been idle for some time, inspect the check valve for leaks.

这个答案有帮助吗?

得分 4
添加一条评论

pythagorasgp , This is what a lot of the BMW forums are saying, Very common issue, the culprit is usually a leaking check valve. I also found a good link for you to read through that goes in depth of the issue even from earlier models.

http://www.e90post.com/forums/showthread...

这个答案有帮助吗?

得分 2
添加一条评论

If it's very cold by you, sometimes ice can develop in the hose supplying vacuum to the brake booster (or check valve). The water could possibly entered the system during your recent service. Just a possibility.

这个答案有帮助吗?

得分 0
添加一条评论

Most of the car's brakes are assisted by vacuum. If you pump the brakes off your car, you get to find a normal pump, and they in due course of time hardens as the vacuum reservoir gets exhausted. Now if your car is being used for weeks together, the vacuum might recede as the system isn't designed to hold the vacuum for long, and that’s why you tend to get the hard pedal feel. You can test this hypothesis easily by turning off the car and pumping the brakes.

The probable reasons and frequent solutions to get rid of the hard brake pedal are:

Vacuum or lack of vacuum pressure is the most common cause of a hard brake pedal, and therefore, it is the foremost thing to look at when the brake pedal becomes rock hard. Another possible reason for a hard pedal could be the combination valve and in particular the Pressure Differential Valve within it. A thorough inspection of the whole system should help you identify such underlying issues of a hard brake pedal.

If you are completely unaware and do not know how to take the correct action, engage a professional mechanic at Eurobahn BMW MINI Mercedes-Benz Audi of Greensboro.

这个答案有帮助吗?

得分 0

3条评论:

Could putting on new breaks and caliper-Core be the reason why my breaks are hard ?

完成的

Do they just need breaking in

完成的

Could the lack of vacuum also prevent the egr valve correctly opening and cause an insufficient flow code?

完成的

添加一条评论

I had spongey brakes and had replaced booster. rotors and all brake pads. I tested brakes and heard a click and felt a slight click in pedal, this only happened once when pumping the brakes after replacing new parts. I bought new master brake cylinder and tested brakes again. brake pedal stiff and brakes do not release until i bled one brake caliper and or unplugged the vacuum hose on booster, then the brakes released. went back and forth trying to find any issues, bled the ABS valve, still stiff brakes with no release. The remedy/FIX ... I compared the center pin with the old booster pin, ( on the booster that plunges into the master cylinder ) and the new booster pin was 1/16th an inch longer. I swapped out new pin with the old one. brakes work great as they should. Hope this helps someone else with this kind of issue, PEACE

这个答案有帮助吗?

得分 0
添加一条评论

添加你的答案

pythagorasgp 将永远感激不已
浏览统计数据:

过去 24 小时: 2

过去 7 天: 30

过去 30 天: 220

总计 102,303