Astra brake drum removal / general braking problem

[JimBobUK]

Hi All,

I'm trying to figure out what is wrong with the braking on a 95 Astra 1.4 (No ABS)... Braking is poor / spongy.

I don't believe that there is a problem with vacuum, as pumping brake a long time after engine stop indicates vacuum is still present.

I first tried bleeding brakes through, but this did not seem to improve braking at all - not even for a short time, and I didn't notice any air coming out during the bleed.

I was thinking of the master cylinder / servo, but does the fact that the bleeding didn't even temporarily improve matters eliminate the servo from the enquiry?

I don't know how may ways a servo can fail - it is usually related to air ingress to the system?

Anyway to get to the original point of the post...

I was going to take a look at the drums to see if there is some issue there - not really sure if they can lead to this symptom though.

I can't get the drums off though! They have presumably worn a lip on the drum, and I probably need to release the auto adjuster to get the drum off. How might I accomplish this? I see 2 rubber bungs in the back of the hub...

Under one of the bungs is a tiny plunger - which perhaps is something to do with releasing the adjuster. Doesn't seem to work - so not sure...

Can anyone make any suggestions about the overall braking problem, or my current problem getting the drums off?

Any advice would be greatly appreciated.

Thanks all,
James

 

[johnwr]

Your right about the rubber plug in the back plate, remove the plug and use a screwdriver to press on the end of the handbrake lever and this will you more clearance between drum and shoes then the drum should come off fairly easily.
regards johnwr

 

[iain90210]

I have removed lipped brake drums by bolting the road wheel back onto the drum. It gives you something bigger to get hold of! At the risk of stating the obvious the car must be properly supported if you use this method, e.g. axle stands. You don't want your wrists squished between the wheel and the wheel arch!

Bear in mind that if you have to use significant force to get the drum off you may damage the wheel bearing. Hopefully johnwr's tip will let you take them off without too much difficulty.

 

[JimBobUK]

Thanks for the advice guys... Will try again a bit later on... Not sure I'd recommend bolting the wheel back on, as the threads go into the hub - not the drum.

I got some advice from a master tech mechanic last night... He recommended looking through the bolt holes into the drum, and inserting a screwdriver to 'ping' off the auto-adjuster.

He also modified my approach to brake bleeding - I was bleeding using gentle pedal pressure. He recommended stamping the pedal several times then maintaining heavy pressure while releasing fluid from the nipple. This method would be better to shift trapped bubbles of air.

 

[johnwr]

jimbob, if you read my last posting, this is the easiest method of gaining enough clearance to remove a grooved drum. I think your "master tech mechanic" what ever that means is going to do more damage to the adjuster mechanism trying to back off the adjusters through the wheel bolt holes. To back off these adjusters you need to pull back the ratchet then rotate the adjuster wheel, not easy through a 12 mm hole. Bleeding the brakes on astra's is usually easy, just put a bleed pipe on the nipple and slacken and the fluid/air comes out without any need for any excessive pressure on the pedal. But if the brakes are spongy then there is a good chance you wil need new wheel cylinders.

regards johnwr

 

[iain90210]

'One man' bleeding kits, using air pressure from your spare tyre, are by far the easiest diy way to bleed you brakes and very effective.