Volvo 740 Estate Auto 1988 - Brake Calipers - ABS - 2316cc

[Xylonite]

I am new to this Forum so apologise if I haven't posted correctly. My problem is that my Volvo 740 needs new Brake Calipers on all four wheels plus brake pads, the discs are fine but I am considering changing those at the same time. The problem we are having (mechanic doing the work - very good mechanic but IT is not our thing) is sourcing the correct ones for the car as all our usual sources cannot get them. I have looked online and various places say that I can still get them on online car parts sites - autocar and europarts etc but am worried about getting the wrong ones. Any help or advice would be appreciated. I've had the car about 18 years and it has always past MOT first time so it deserves to have the money spent on it I've just always been used to getting parts locally if needed. Thanks very much for any help you can give. The mechanic looked at cleaning them up but they are too far gone for that. Car is automatic and wasn't used to much during lockdown unfortunately which didn't help. Thanks again.

[Challo]

Do you know what the issue is with the calipers?

Bigg Red is the best option for either rebuilding your standard calipers or they can send you the rebuild kits. https://www.biggred.co.uk/

On mine the seals had perished and its meant the pistons wouldn't retract. Ordered the re-build kits and my mechanic did the work.

[tofufi]

Welcome to the forum

There are a couple of types of caliper so best to make sure you get the right ones - I'm sure others are more knowledgeable than me

I've heard good things about Bigg Red.

[TonyS9]

The calipers often clean up just fine with sand blasting and rebuild kits are normally available along with replacement calipers. Its just that mechanics often don't want to get involved in rebuilding, especially if they need blasted.

Assuming they are correct and the bores are pitted or something, I normally recommend brakeparts.co.uk, but the site seems to be broken at the moment and the "select version" is stuck. Although you havn't provided enough information for this anyway.

I don't know the 740 but think rears will be similar to the 940 and be either 38 or 40mm piston ATE fixed caliper with 2 pistons. You can read this on the side but it may need attacked with a wire brush first.

Front calipers vary much more, and you need to clearly identify the disk diameter, offset, caliper types (sliding/fixed) and piston diameter.

Depending on the type you might need a new bracket or sliding pins (this often sieze).

Some photos and measurements may help others identify the calipers.

[Challo]

Originally Posted by TonyS9

The calipers often clean up just fine with sand blasting and rebuild kits are normally available along with replacement calipers. Its just that mechanics often don't want to get involved in rebuilding, especially if they need blasted.

Assuming they are correct and the bores are pitted or something, I normally recommend brakeparts.co.uk, but the site seems to be broken at the moment and the "select version" is stuck. Although you havn't provided enough information for this anyway.

I don't know the 740 but think rears will be similar to the 940 and be either 38 or 40mm piston ATE fixed caliper with 2 pistons. You can read this on the side but it may need attacked with a wire brush first.

Front calipers vary much more, and you need to clearly identify the disk diameter, offset, caliper types (sliding/fixed) and piston diameter.

Depending on the type you might need a new bracket or sliding pins (this often sieze).

Some photos and measurements may help others identify the calipers.

I think it really depends on the issues. Mine the seals where shot and letting lots of crap in and causing them to seize. If time is not an issue OP can send the calipers to Bigg Red and they will refurb for him.

Re-Build kits are pretty easy for a mechanic as they just need to press out the pistons and add in the new ones.

[360beast]

+1 for Bigg Red, I'm lucky that they're only 10 minutes away so I can pop in and drop stuff off etc. Really great bunch of guys in there, they gave me discount on some parts once "because it's Friday"!

[kiloran]

The full Volvo parts catalog for the 740 years 91-92 is available here (big download) - http://www.volvotips.com/parts-catal...ts-catalog.pdf

On page 11 & 12 of this catalog it will show you how to decode which brake setup you've got - based on the final digit of the 2nd line of the product info section of your VIN plate. It will also have the original Volvo part numbers which may aid your search - the braking section starts around page 578.

If it's just pistons sticking then a rebuild kit will be the best option, it's easy if you've got compressed air to hand to pop out the pistons, clean up the bores, and fit new seals from the rebuild kit.

Just had a quick look and PFS has calipers in stock - you just need to decode your product plate to determine which you need - https://www.partsforvolvosonline.com...p?cPath=52_511

[kiloran]

Oh and the marking (38 or 40) which Tony refers to is on the outside central barrel of the caliper near the "nipple"

[jasons]

Mechanics don't like cars taking up ramp time, nor immobile cars so whilst rebuilding them sounds like a great idea and one I'd do, I doubt you'll find a garage wanting to do it.

Your local garage will probably just want to fit exchange calipers, and its really for them to sort that.

You may find that the actual piston seals are good, but you may have a couple of dust covers that need replacing.

I've just done a 240 and 940 front and rears, out of a total of 18 dust covers between the two cars 5 needed replacing.

The worst pistons were on the 240 whereby I needed both 10bar of pressure and heat to move the piston, but it came out.
All the callipers were completely serviceable, you can use other methods to clean off the rust other than blasting assuming you can have the car off the road.

I was in no hurry on either, but 7-10 days per car with the longest process being rust, but now they all look like brand new calipers and the pistons move freely, with the caliper off the pistons can be pushed back by hand and only need 20psi to have them moving out.

I don't know if the 740 has 4pot front calipers or single pot with sliders, I can't see the 4-pots being cheap on exchange, but single pot sliders are usually pretty cheap exchange.

One thing I found was the dust covers for the 240 front and rears were the same size as the 940 rears, I wouldn't be surprised if piston sizes are the same accross models either.

[Laird Scooby]

If it has ABS it will have single piston sliding front calipers. I would hazard a guess from everything you've said that cleaning up or renewing the slide/guide pins on the front calipers and ensuring the pistons are free to move will sort the problem for you.

Similar with the rears except they are twin piston but new guide pins assuming the pistons are free to move will almost certainly sort your woes. I'd also suggest new pads all round and a complete flush/change of brake fluid - it's hygroscopic so absorbs water and if it hasn't been changed recently then would also go a long way to resolving the problems. Also less chance of popping your master cylinder if you get it changed sooner rather than later!