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2008 Honda Accord: How I managed to remove stuck brake master cylinder

6th January 2023, 11:11 by Dev Shah

According to the mechanic , if they force the part out, it would not only damage the original 'Brake Master cylinder'. This is something that I can allow, as I already have the replacement.

BHPian ritedhawan recently shared this with other enthusiasts.

I have been using a Honda Accord 2008 2.4L AT which has clocked 120,000 KM. Recently I went to an independent workshop to get the 'Brake Master Cylinder' replaced. However, once the mechanic unscrewed the 2 bolts which allows the component to stick to Brake booster and disconnected the short cable on the left of the brake master cylinder. He was 'Unable to remove the Brake Master Cylinder'. It seemed as if the 'brake master cylinder' is stuck to the brake booster!. Initially, he tried to pull it out as usual , nothing changed. Then he tried to apply additional force, still no change. Then he got some 'rust penetrant ' and applied where the 'brake master cylinder' sticks to the Brake booster. He tried again to pull the part, no change. He applied the 'rust penetrant' again and we waited for 1 hour and then tried to pull the part. Still no change.

The mechanic and his service advisor came to the conclusion that: they cannot disconnect the part and forcing it out may incur damage not only to the part but to the connected 'Brake Booster'. We collectively decided to give up the part replacement. They re-installed what was taken off during this procedure.

Let me now elucidate in detail , what required the change of the 'Brake Master Cylinder':

Its been months now that I have been facing this peculiar issue : The brake comes into effect only when the brake pedal is pressed sufficiently. For example, for the initial press of the 'Brake pedal' , nothing happens. Lets say, that the 'brake pedal travel' is being measured on a scale of 1-10. For the initial '1-4' brake press , nothing happens. Brake comes into effect between '5-10' on the scale. I keep on topping up 'Brake fluid reservoir'. Initially, I went to the same workshop which recently attempted the part replacement (WoS, Noida). There the mechanic and SA mentioned 'Brake Master Cylinder' being the culprit. I got the same diagnosis from another workshop. I have checked some YouTube videos and they confirm the fact that its the 'Brake Master Cylinder'. Therefore, when I went to the independent workshop , I had procured the AFM Brake Master Cylinder. However, what can we do if the originally one is stuck and wont come out?

This is where I need advise from fellow T-BHPians:

What can we do IF we are unable to replace 'Brake Master Cylinder' as it seems to be stuck to the 'Brake Booster'?

I would like to inform all, that we have already done the brake bleed and it makes marginal difference to the issue. According to the SA and mechanic , if they force the part out , it would not only damage the original 'Brake Master cylinder' --This is something that I can allow, as I already have the replacement-- But it would damage the brake booster as well. This is what I fear. That is the reason we aborted the replacement. But then I am stuck with the same issue.

My constant fear is: If they force the part out albeit damaged and then on top of that the brake booster has incurred damage as well. Then I may have to get the Brake Booster replaced as well.

Lets continue with the same line of thought and we decide to replace both. What guarantee that the original brake booster wont cause the same problem that the 'Brake Master cylinder' is causing. The problem: unable to remove it.

So, finally, day before yesterday, took some time to get the car to the repair shop in order to get the pending replacement job done. The OEM brake booster, brake master cylinder, and OEM Dot-3 brake fluid had arrived and been lying dust at my home. The job of detaching the old brake master cylinder from brake booster and getting brake booster out from the engine bay in itself required two to three hours. There wasn't enough space to get the brake booster out, the mechanic had to get the AC line out which lead to the release of any existing AC gas in the system, the strut bar had to be removed, we didn't remove the power steering hose as stated by fellow Bhpian 'vigsom'. However his advice was really helpful in terms of getting the job done.

Once the old parts were out, getting the new brake booster installed was time consuming. The replacement job started at 1145 and by 4 PM we had the old parts out and the new brake booster installed. Then the new brake master cylinder was installed and filled with OEM brake fluid. The peripheral parts taken out to get the space required for the brake booster were re-installed, AC gas refilled, then started the final phase of brake bleeding and test drove the vehicle to check everything was in order.