Front right brake caliper piston is stuck (1980 Vanagon)

[tfelzq]

I purchased this old vanagon used and the previous owner didn't know anything about the last time anything had been done to the brakes or calipers.

Went to check my brake pads and the front right brake caliper piston is stuck. I cannot move the rotor. I'm asking for your opinion -- can I replace the front right caliper + pads and replace only the brake pads in the left? Or is it important to replace both calipers at the same time?

Bracing myself for the opinions....

[Ahwahnee]

I see no reason why you would need to replace calipers in pairs. If the other one works well and does not leak than new pads on both sides is what I would do.

[Zeitgeist 13]

It's generally good practice to replace pads and rotors in pairs, but the calipers are probably ok to do by the piece...but if one was prone to sticking, then assuming they're the same age, it's probably likely that the other will be following suit soon.
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Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[MarkWard]

Carefully see if you can open a bleeder valve. Hydraulics may be holding the caliper on, not the caliper itself.
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[IdahoDoug]

Would this be a good time to gore the ox where some people believe the inner brake hose can deteriorate and block the hose - locking the caliper piston from retracting?

Anyhow, are you sure its an issue with the piston or could it merely be the much more likely condition of the pad rusting to the rotor? I cannot imagine a scenario where the front piston has pressure behind it while sitting for years that keeps it pressing against the rotor strongly enough to lock it in position. However, I can easily envision a brake pad getting rainwater and corrosion under the pad and over time creating a bond to the raw steel.

Take a better look and see if you simply need to unlock the pad(s) from the rotor. It will leave an imprint of the brake pad that a 3M abrasive pad or some rough sandpaper will easily remove. You'll be well advised to push the piston in a touch as well as it may also have a ring of grunge in there as well.
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1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[Wildthings]

Rebuilt calipers can be had for about $60 a piece, a full set of brake hoses for less than $100 and pads for between $15 and $80, open your wallet and go for it.

[MarkWard]

Doug, I have to wonder how many front brakes you have done in your life, that you have never come across brake hoses that have swelled up internally and are acting like pseudo check valves.

Believe it or not, it happens. I am not there, there are no pictures for me to see. I don't know how much effort is being put into turning the wheel assembly. It takes a moment to open a bleeder valve and relieve any residual pressure.

Assuming Doug is correct and brake hoses don't swell internally, then the caliper needs to be removed. The early vanagons have dual piston calipers unlike the later vans. After 37 years, the Pistons if you can safely remove them without pinching a finger, will probably be rusted and pitted beyond use.

On my 82, I rebuilt the entire brake system including new ATE calipers. Oh and the 4 flex hoses. My preference when restoring a vehicle is to address systems in their entirety rather than piece meal it, especially where brakes and fuel are concerned. Do it right and do it once. Fortunately the parts are still available.

If you decide to rebuild the calipers, you can use the brake hydraulic pressure to force the pistons out of their bores. Because you have two pistons, you will need to secure one while you remove the opposite one. A thin piece of wood will keep you from damaging the piston and watch out for your fingers. Quite a bit of force can be released. Calipers that are not physically seized can be serviced with compressed air. To hone the caliper bores, you will need to split the caliper in half. Make sure you have the tiny O rings that seal the halves before splitting them. Otherwise you'll need to use some Emory cloth to clean the bores the best you can. Some brake paste will help with reassembly.
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[Butcher]

Attacking a brake job where the #1 priority is money is a bad way to start.

Could you only replace one caliper? Sure, it's your car and you can do what you want. Knowing that it's possible the caliper is almost 40 years old, I think it's a no brainer on what to do.

As for the hoses, they are pushing the big 4-O too. Why would you not change them for about $15 a piece? I've done my fair share of brakes in the 35+ years of turning wrenches and it's rare, but I've seen brake hoses turn into diodes.

Honing calipers, seems to be a waste of time since the bores are not the sealing surface. The pistons are. I would not waste my time. If I knew the 40 year old calipers were seized, I would not even bother fighting to get them apart only to find out the pistons are NFG. Buy rebuilt units.

Do yourself and everyone else on the road, do it right now. If you do not have the money, wait till you do. Buy quality parts. If the vehicle is a rust bucket, beware that everything you do could be a huge project. Brake lines do not like to come apart with regular wrenches and sometimes do not come apart with good line wrenches either. Do not paint yourself into a corner.

[IdahoDoug]

If you have more time than money, then you can buy the brake caliper rebuild kit for about $11 from Van Cafe. I have two sets on the bench planning to get to that one day. As noted, you'll be able to use the brake pedal to slowly push the brake pistons out one side at a time - post if you're wondering about this.

I've done a dozen rebuilds like this and find the work easy and straightforward. Or an entire caliper is reasonable as well. I've also had good luck with Van Cafe's braided brake lines. If you're going to keep a vehicle like this for a long time, the brakes are a good investment. As noted, get the proper brake line wrenches if you go that route. They're notoriously easy to strip and those help prevent it. I'd put PB Blaster on the connections for a couple weeks, and I'd have a propane torch on hand to help loosen it on the big day.

Doug
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1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[vanagonjon]

Replace everything that you can. Look at the brake lines that run to each each wheel, if you see any corrosion replace them. Copper nickle lines are easy to bend but do not look as slick as the factory lines. Get a good ISO 'bubble' flare kit, you can find a good used one on Ebay. As everyone has chimed in, 40 year old brake components are in need of replacements. If you have any reservations on rebuilding your own calipers, buy rebuilt ones.

John

[IdahoDoug]

Good point on the brake lines, and they're not difficult. I've been making my own metal brake lines from bulk for over 40 years - just did some last month. Myself or others here can lead you through the process. NAPA's currently got a grade of brake line that's easy to work with and available in rolls.
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1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[DanHoug]

my rebuilt Girlings didn't come with the short, steel line for the brake hose connection on the caliper and one broke (rust) while removing it. easily made a new one with the CuNifer line as it bends so easy!

-dan