[ChrisRinai]

hello,

i'm having major issues with my brakes ( 1985 Sierra Hardtop ) after replacing everything, as in have no pedal.

i have done/replaced:

master cylinder
front pads
seal kits and new pistons in front calipers
rear wheel cylinders
rear shoes
new drums
brake bleeding/new fluid

the problem is no matter what i do i have no rear brakes, as in the rears don't work but the front does. they have been bled many times, everythings, visually, is as it should be as far as i know. when i lock off/clamp the rear lines ( clamp the rubber sections going over the diff ) the brakes ( fronts ) work fine, have proper pedal etc. as soon as i un-clamp the rears i end up with no pedal again?? anyone have any ideas on what i may have done wrong or what else to do/check??

cheers
Chris

[royce]

did you adjust them properly?

[ChrisRinai]

royce wrote:

did you adjust them properly?

that's the bit i can't figure out, they seem to be adjusted as far out as possible but dont seem to come out far enough? if that makes sense

[twitchy]

I'd re-check the adjustment on the rears & see how you go. You didn't have any bits missing or left over??????

[Scrawny]

My guess is wrong shoes, there's two different sizes. Did you compare them before fitting? If not then compare them now

[SierraDan]

Can the different ones even go in?
I got the small ones when i needed the big ones once, and it physically wouldnt go one the handbrake/adjuster thing.

[Scrawny]

I managed to fit some when I was in hurry once, had the same thing happen

[ChrisRinai]

did some mearsurements and it looks like the new drums are too big in internal diameter! the shoes are adjjusted as far out as possible and still dont touch the drums hence the no rear brakes!! how or why i dont know but here is between 8 and 10mm difference between the diameter of the drum and the shoes fully adjusted out.

[Scrawny]

Wrong size shoe. There are two different size drum on Sierras, I think they are something 180 and 200mm

[ChrisRinai]

i dont think its the shoes, i have the same as what came off. drums measure around 228mm internal diameter and say maximum 230mm, shoes measure at 220mm fully adjusted out as far as they go.

[Scrawny]

Have you compared shoes by eye or by placing new and old together?

Are the wheel cylinders right?

[ChrisRinai]

Scrawn wrote:

Have you compared shoes by eye or by placing new and old together?

Are the wheel cylinders right?

yes and yes, old and new shoes are identical and wheels cylinders are the same as what came off. the only thing we can find nt\ot right is the drum size?

[Scrawny]

So you have the bigger drums meant for the bigger shoes then.

[royce]

ChrisRinai wrote:

new drums are too big in internal diameter!

put the old drums on?

[ChrisRinai]

i posted all this before we realised the drums could have been wrong!!!

old drums were well cactus so got chucked, fingers crossed it'll be sorted tomorrow as i rang the shop that i got all the parts from and it looks like thay have the smaller drums available. it sucks though cause i told them all the info required and they never said anything about there being different sizes of shoes and drums! wouldn't have had all this head f*#k if they had have said to check the sizes or said there were differences

[ChrisRinai]

wrong sized drums it was! all sorted now

[cairns27]

I had a hell of a time adjusting the back brakes on my '87 LWB NT.

At the end I had to use a screwdriver and lever the shoe out, and the adjuster sprung out and took up the slack.

Pedal ok now, but after a drive, one drum is warm, the other cold.I'll pull it apart and adjust it out a bit more.

How's it done? Is there an easier way?

bye

[86slowsierra]

wtf. arnt all the drums self adjusting? except the handbrake.

[ChrisRinai]

once i had the correct parts mine was a piece of piss, the adjusters did their own thing and adjusted up nicely, i just had to close them up to get the drums on then a couple of pumps on the pedal and all was good. brakes feel bloody good now!

[christover1]

86slowsierra wrote:

wtf. arnt all the drums self adjusting? except the handbrake.

My 1.0 litre LWB did not have self adjusters,
until I upgraded to 1.3 brakes.
I don't know if other models also didn't have self adjusters.
The 1.3 brakes were much nicer,
but not as nice as the later disc conversion.

[Scrawny]

cairns27 wrote:

I had a hell of a time adjusting the back brakes on my '87 LWB NT.

At the end I had to use a screwdriver and lever the shoe out, and the adjuster sprung out and took up the slack.

Pedal ok now, but after a drive, one drum is warm, the other cold.I'll pull it apart and adjust it out a bit more.

How's it done? Is there an easier way?

bye

Are your brakes full of mud? I'd be stripping them apart and making sure everything works properly. Free up and grease the adjusters. Are all the springs fitted correctly?

[cairns27]

All brake parts look as new.Springs on right???Took one side off at a time,but everything seemed to work.

I just can't see why one side remains cold, not working at all?

bye

[jmrc94]

Hello,
I need help with the brakes on my '89 Sierra W/T.

The handbrake cable appears too long even when fully adjusted. When driving the handbrake lever must be on to make the brake pedal work properly, otherwise it goes to the floor. we put a spacer in the cable the keep tension and now the lever moves only seven clicks but does not work - only makes the pedal brakes work better still. When the handbrake is on the shoes don't seem to come out far enough, only a few millimeters. My drum is 220mil, the same as my friends N/T but it seems as though my shoes aren't extending far enough to reach the drum. The adjusters are fully extended too.

Any help will be appreciated. Thanks

[Bruce]

Is not Royce trying to help you on another post?

[mrw82]

jmrc94 wrote:

Hello,
I need help with the brakes on my '89 Sierra W/T.

The handbrake cable appears too long even when fully adjusted. When driving the handbrake lever must be on to make the brake pedal work properly, otherwise it goes to the floor. we put a spacer in the cable the keep tension and now the lever moves only seven clicks but does not work - only makes the pedal brakes work better still. When the handbrake is on the shoes don't seem to come out far enough, only a few millimeters. My drum is 220mil, the same as my friends N/T but it seems as though my shoes aren't extending far enough to reach the drum. The adjusters are fully extended too.

Any help will be appreciated. Thanks

Have a look here. This fellas having a similar problem.
viewtopic.php?f=5&t=32566

[Bruce]

Bwhahahahahaha

[jmrc94]

thanks for the link. dont know how i missed that one...