Brake pad replacement - bleeding

Ozric · Post by **Ozric** » Fri Jun 23, 2006 2:14 pm

I've just read the factsheet for changing the brake pads. Do you not need to bleed the brakes after fitting?

I'm not a real mechanic!!

Simple Simon · Post by **Simple Simon** » Fri Jun 23, 2006 2:55 pm

I stand to be corrected by the experts on the forum, but I don't believe that bleeding should be necessary. Provided that you don't break into the brake hydraulic system! Just be careful that when you ease the pistons back into the calipers you don't force brake fluid out the top of the reservoir. Brake fluid and paintwork just don't get on! Not changed pads on the Bongo yet but did my Mercedes the other week.

tigger · Post by **tigger** » Fri Jun 23, 2006 4:37 pm

Simple Simon's right - no need to bleed if the hydraulic circuit is not 'broken' - and it isn't when you just change the pads. Before pushing the pistons back into the caliper, remove the lid from the brake fluid reservoir and place rags tightly around the neck to catch any fluid that does overflow. Also guard against ingress of dirt into the open reservoir.

When the job's all done, pump the brake pedal to centre the new pads against the disk and then double check your fluid level in the reservoir - adjust if necessary.

By and large, no fluid is lost due to spillage and no topping up is needed - but it's always best to make sure.

tigger

Ozric · Post by **Ozric** » Fri Jun 23, 2006 8:45 pm

Thanks for the info. Ingress is also an interesting word, I must use it more often.

Cheers!!

alant54 · Post by **alant54** » Fri Jun 23, 2006 10:57 pm

Do not expose your brake fluid to the atmosphere for any longer than necessary..it attracts moisture like a sponge....leading to boiling when hot and brake fade....Alan

tigger · Post by **tigger** » Tue Jun 27, 2006 4:27 pm

'Ingress' is a good Haynes Manual type of word I reckon. They say that a picture speaks a thousand words, but in a Haynes Manual, a word often speaks a thousand hours of fruitless swearing and cursing. For example, the Haynesian phrase 'drift the bushing off the spigot' usually translates roughly as follows:

'Try and remove the bushing and discover that it's seized solid, like it always is. Pull harder until hand slips, catching knuckle on something sharp. Treat injured knuckle. Get molegrips, g-clamp etc on bushing, to no avail. Visit shop to purchase expensive bushing removal tool. On return, find that there is no room to get tool onto bushing. Try WD40, heat, hammering etc, causing abundant collateral damage but no result. Intermittent swearing to continue throughout operation....'

This is a bit off-message I know, but I think we've said all anyone needs to know about whether or not you need to bleed the brakes after doing the pads. And we've also touched on the need to guard against EGRESS of brake fluid from the reservoir when pushing the cylinder back into its housing - 'egress' being the opposite of ingress of course and another good Haynes word.....

tigger (just eaten a thesaurus)

carliol · Post by **carliol** » Tue Jun 27, 2006 6:21 pm

Not sure you should be messing with your brakes with your knowledge . A garage will do it correctly and safely for a few quid.