Seized calliper, red hot brake. Where to get seal kit pls?

[volvoid]

hate to say it, but by far the cheapest place is usually ebay. Some even px the old unit

[rusty244]

Time for an update, sorry been crazy busy..

After further testing we determined the handbrake was fine and not binding in any way and there was no blockage in the brake hoses.

The piston on the suspected dud caliper was mightily difficult to lever back in and made a clunking sound on doing so. So we ordered a recon cailper for a reasonable price (£40ish I think).

Got this fitted and brakes then back to operating normally.... For the next 3 days (c.50 miles) at least.

Then midweek last week the "Brake Failure" warning light came on, uh oh - this is the first time this has ever triggered on this car. There was no drop in brake fluid level, and the only symptom was having to press the brake pedal slightly further.

Went back to the mechanic who suspects there is air in one of the brake circuits. When it was bled for the new caliper going on, he only bled from the line on the new caliper, and from what I could see the pedal was pressed down pretty far each time he did this.

I'm now slightly concerned after reading the recent brake bleeding thread on here that the master cylinder might have been damaged through the somewhat furious brake bleeding.

Anyway, going back on Wed to have the brakes bled further which will hopefully solve the problem and eliminate the warning light. Assuming he is just going to do the same on the one wheel again..

Just in case this does not fix the warning light, any other tips for how this should be done correctly that I can request are carried out?

[julianps]

I've just been down this road too; had a seized rear (type 1; Girling) which I found to have type 2/ATE pads and pins in. I got a caliper from Brake International and it went on fine.

Bleeding the brakes is not so easy though.

The brake system is made up of four components; master cylinder+vacuum assist! a warning light thingy in-board of the near side front wheel, (two) pressure adjusters on the ear axle and four calipers.

The master cylinder has two unequal sized chambers called primary and secondary. When the brake pedal's pressed primary cylinder pressure closes either the leading or trailing edge of the front calipers (depending pre or post '77 models) first then as pressure is applied further the whole front pad is applied. But not the rears.

The pressure adjusters at the rear equalise the disproportionate pressure of the primary and secondary cylinders and apply rear braking only under extreme pressure. So much so that Volvo dealers use a pressure bleeder with 60+ psi to bleed the rear brakes. An EEZYBLEED with max 20psi stands no chance without considerable foot-pressure too.

Another challenge is the brake warning light system thingy. If the primary or secondary circuit loses pressure a plunger is push by the circuit with pressure so that a) it blocks off the circuit with no pressure (to preserve fluid); and, b) earths the warning light to tell the driver of a fault.

Applying excess bleeding pressure to one circuit will have the same effect; it'll push the plunger too far over and bleeding results will be erratic. Ha-ha-ha-Haynes suggests a solution to all of this but it's only partially effective.

Volvo suggests for manual bleeding you do the following;

1. Jack up the front of the vehicle and remove both road wheels and press the brake pedal hard a couple of times to discharge the vacuum assistance.
2. Using a jar and three bleeder hoses open all three bleed nipples on the front offside wheel (the longest run from the master cylinder). With an assistant pressing the pedal about 10 times, bleed off all air (note that this balances the bleed across both primary and secondary circuits and keeps the brake warning switch disengaged). Close the three nipples.
3. Press the brake pedal hard about three times to self centre the brake warning valve.
4. Repeat the task at #2 above on the near-side caliper. Once complete repeat the task at #3 above.
5. At the rear fit one hose to each caliper and open the bleed nipples. Leave for 15 minutes ensuring the fluid level in the reservoir does not go down too low. Yes, Volvo says to gravity bleed the rears because the pressure you need to overcome with pressure system could damage the warning switch system.
6. Tighten the bleed valves, refit the front wheels and lower off stands. Road test and repeat if necessary using only three to five presses of the pedal when re-bleeding the front.

This was taken from a PDF at K-jet.org and I can vouch that it worked better than the Haynes method, which along with a "falling" EEZYBLEED and fluid going everywhere had me somewhat stressed. Brake now booootyfulll.

[Clifford Pope]

That is why I never bleed brakes. I quickly blank off the pipes when I remove any component to prevent fluid loss, and bench bleed the new hose, caliper, etc, filling it right up and plugging the entries.
Then refit, and quickly connect up the hoses, leaving them 1/2 turn loose. Then very gently press the pedal to expel any air through the slack joint, and tighten up.

"Vigorous bleeding" is to be avoided at all costs.

[Stephen Edwin]

Originally Posted by julianps

I've just been down this road too; had a seized rear (type 1; Girling) which I found to have type 2/ATE pads and pins in. I got a caliper from Brake International and it went on fine.

Bleeding the brakes is not so easy though.

The brake system is made up of four components; master cylinder+vacuum assist! a warning light thingy in-board of the near side front wheel, (two) pressure adjusters on the ear axle and four calipers.

The master cylinder has two unequal sized chambers called primary and secondary. When the brake pedal's pressed primary cylinder pressure closes either the leading or trailing edge of the front calipers (depending pre or post '77 models) first then as pressure is applied further the whole front pad is applied. But not the rears.

The pressure adjusters at the rear equalise the disproportionate pressure of the primary and secondary cylinders and apply rear braking only under extreme pressure. So much so that Volvo dealers use a pressure bleeder with 60+ psi to bleed the rear brakes. An EEZYBLEED with max 20psi stands no chance without considerable foot-pressure too.

Another challenge is the brake warning light system thingy. If the primary or secondary circuit loses pressure a plunger is push by the circuit with pressure so that a) it blocks off the circuit with no pressure (to preserve fluid); and, b) earths the warning light to tell the driver of a fault.

Applying excess bleeding pressure to one circuit will have the same effect; it'll push the plunger too far over and bleeding results will be erratic. Ha-ha-ha-Haynes suggests a solution to all of this but it's only partially effective.

Volvo suggests for manual bleeding you do the following;

1. Jack up the front of the vehicle and remove both road wheels and press the brake pedal hard a couple of times to discharge the vacuum assistance.
2. Using a jar and three bleeder hoses open all three bleed nipples on the front offside wheel (the longest run from the master cylinder). With an assistant pressing the pedal about 10 times, bleed off all air (note that this balances the bleed across both primary and secondary circuits and keeps the brake warning switch disengaged). Close the three nipples.
3. Press the brake pedal hard about three times to self centre the brake warning valve.
4. Repeat the task at #2 above on the near-side caliper. Once complete repeat the task at #3 above.
5. At the rear fit one hose to each caliper and open the bleed nipples. Leave for 15 minutes ensuring the fluid level in the reservoir does not go down too low. Yes, Volvo says to gravity bleed the rears because the pressure you need to overcome with pressure system could damage the warning switch system.
6. Tighten the bleed valves, refit the front wheels and lower off stands. Road test and repeat if necessary using only three to five presses of the pedal when re-bleeding the front.

This was taken from a PDF at K-jet.org and I can vouch that it worked better than the Haynes method, which along with a "falling" EEZYBLEED and fluid going everywhere had me somewhat stressed. Brake now booootyfulll.

Thank you, and ... is that front offside as longest run the same for a UK RHD vehicle?

[DW42]

A few years ago on my '88 I had to replace the brake line from the rear driver's side caliper to the rear brake line junction (it's a long section). I struggled to get it bled, and resorted to attaching a narrow rubber line between the caliper bleed nipple and my Pela oil extractor. I pumped the Pela up to quite a strong vacuum and also gently pressed the brake pedal until the clear section of line on the Pela was all clear of air bubbles. I did it on my own, so had to keep moving between checking the line for bubbles, pressing the brake, and topping up the reservoir. I don't know if attaching an oil extractor could damage the master cylinder, but I got away with it, and it was easy once I worked out the method.