I have a 88 240. Brake fluid was dark, so I decided to flush brakes. Brakes worked fine.
Bled brakes, by myself, with a catch bottle and tube; Fill res. Loosen bleeder. Pump brakes, refill res, etc. until clear fluid is seen in catch bottle. I did FL, FR, LR RR. LR was extremely hard to push fluid through, RR almost impossible. I could get maybe 2 oz. fluid out of LR caliper after VIGOROUS pressure on brake. Very abnormal. Now brake light is on, and brakes are crap. When in reverse, it feels like brakes are binding. I have been flushing brakes for yers, and never had a caliper that would not flow fluid easily.
What have I done? Very frustrating

"LR was extremely hard to push fluid through, RR almost impossible. I could get maybe 2 oz. fluid out of LR caliper after VIGOROUS pressure on brake."

Try removing the bleed screws completely. Dirt has probably built up in the system, so a larger opening may be needed to clear a clog.

Don't replace the MC until you know it's bad. Ie. pedal slowly drops to floor under steady gentle pressure (as at a stop light).
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1980 245 Canadian B21A with SU carb, M46 trans, 3:31 dif, in Brampton, Ont.

"Try removing the bleed screws completely." I tried that with no change in blockage. I will remove the flexible brake line next, to see if it is blocked.

Having had this problem on a 1990 and a 1991 I would strongly suspect the flex lines over the rear axle. Be very careful when dealing with the rear hard lines, they seem to be unobtanium at this point. I got the 1991 back on the road after twisting off a hard line end only through the generosity of a fellow Brickboarder near Baltimore.

1991 240
1990 240 DL (parts)
1992 945T

If you bleed your brake by pumping your brake pedal until it hits the floor, then you have just push the sludge trap in your master cylinder into the seals. You might be able to just remove, clean a reassemble. Power bleeder or vacuum pump is the best method to change brake fluid in an old system. If your brake are binding , then replace your rubber brake lines. They swell on the inside, not allowing brake fluid to return.

I bought a Motive brake bleeder. Wish I had done that 40 years ago.

Bled brakes per Bentley sequence. ( Which could have been written a lot clearer )
Brakes work now but sometimes go to the floor. I ordered a new master cylinder which I will install. It sounds like I pushed the 31 year old master cylinder into the grave by attempting to bleed brakes by pumping the pedal.

"It sounds like I pushed the 31 year old master cylinder into the grave by attempting to bleed brakes by pumping the pedal. "

Happens every time!

"( Which could have been written a lot clearer )"


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Art Benstein near Baltimore

The older I get the faster I was.

Nice having the info on t=your bottle where you need it.
Well, I installed new master cylinder, cleaned out the reservoir, bled brakes with Motive bleeder. Brakes work properly now but brake light is still on.Looks nice having that clean tank full of new fluid. Why is the brake warning light still on?

"Why is the brake warning light still on?"

For 2-series Volvos model year 1975 through 1990, the brake failure warning lamp is switched by a pressure differential sensor (BFWS) brake failure warning sensor called by some the octopus.

If it is on brightly whether you step on the brakes or not, the shuttle in the octopus is probably stuck in gummy o-rings.

If it comes on brightly only when you step on the pedal, you still have air in the system on one side.

If it is on dimly all the time, the switch pin cavity might need a flush with some brake cleaner.


https://www.brickboard.com/RWD/volvo/1327815/220/240/260/280/1990dl_240_non_abs_brake_problem.html
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Art Benstein near Baltimore

"A gentleman is someone who can play the accordion, but doesn't." -as retold by Monte Leister

The light issue seems to have resolved itself. Thank you for the octopus info, and the other help you have provided. (You have helped me out a lot in the past.)

Thanks for the warning.
Since I have some new ones, I will remove the rear flex lines first to see if that is the issue, If not, I will work my way back, starting with the fragile metal lines. Did you try heating the nuts with a torch before removing them?
PS I got one of the pressure brake bleeders to properly bleed the brakes.

Never use the brake pedal to pump the old brake fluid.

If you must, you place some wood pieces to limit brake pedal travel to 1/2 or less of the brake pedal stroke. A helper, then, opens the bleeder with 8mm spanner wrench such as a hex 6-point or like wrench, as you begin the brake pedal press and than closes the bleeder before you reach the bottom of the brake pedal press why.

You do this as there is no useful way to prevent brake fluid passing between the bleeder thread / caliper bleeder threaded bore. Air is always sucks back inside the caliper on the release.

For the same reason, the fluid suction method does not work as air passes through the thread.

You will need a new master cylinder. ATE is OEM.

I urge you do rent or buy a Motive or like pressure bleeder and flush in new DOT 4. Some will say here to bench bleed the MC. Research MS bench bleed. Videos on you tube.

https://www.brickboard.com/RWD/volvo/1662538/220/240/260/280/new_pads_resurface_rotors_hows_brake_fluid_black.html

Read this here that detail my recent bleed on my 1992 240 with ABS:

https://www.brickboard.com/RWD/volvo/1662538/220/240/260/280/new_pads_resurface_rotors_hows_brake_fluid_black.html

You do not have ABS, so in this order from the current Haynes manual (Haynes continues to publish these):



The Volvo 700-900 series FAQ on Non-ABS brakes:

https://www.brickboard.com/FAQ/700-900/Brakes.htm

Questions?

Hope that helps.
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Donate NOW! Give your brickboard.com a big DONATION!!! Find the on brickboard pages!

The ATE master cylinder is way more expensive than one from IPD. Would you be afraid of the IPD cylinder?

As Mr. Yount indicates.

Your description suggests the current master cylinder may be failed as you pressed the brake pedal to far down, pressing the master cylinder piston to deeply (too far?) into the bore. A seal (usually the front seal), if the master cylinder is old, may have failed. I'm unsure whether quality rebuild kits exist anymore from ATE for the OEM ATE brand non-ABS master cylinder installed at the factory, if the MC in your 240 engine bay is original or an OEM replacement.

May have forgotten to mention it may require two complete circuits to bleed the brakes. What is the condition of the flexible brake lines? Any bulges? Are the exterior carbon rubber lines deeply cracked? Replacement of these may be a bother!

ATE is OEM. Sorry. Yet if iPd sells it, it is probably made well enough as after market. Yet quality can vary where the national origin of after market auto parts varies.

Also, best to research different vendors like FCP Euro (and their lifetime return warranty, yet some express both elation and disdain at the FCP Warranty), Rock Auto, and *maybe* AutoZone. NAPA offers good quality after market.

You can find the same part at different retail vendors though today the prices may not vary.

The Volvo OEM for non-ABS 240 is remanufacured with a core charge. PN 8111006
89$ at Tasca Parts in Cranston, Rhode Island.
https://www.tascaparts.com/oem-parts/volvo-master-cylinder-8111006

FCP Euro wants 108$ No mention of a failed core return to refund you 20$ or so.
https://www.fcpeuro.com/products/volvo-brake-master-cylinder-244-245-240-8111006oe

Advanced Auto Entry
https://shop.advanceautoparts.com/find/volvo-240-brake-master-cylinder
See the reviews. My concern is the seal quality. These MCs do not include a reservoir so you reuse your current MS brake fluid reservoir.

AutoZone Entry - Order and pick up at the store. May be in stock if your area has one of the large AutoZone warehousing stores.
https://www.autozone.com/brakes-and-traction-control/master-cylinder-brake-system/volvo/240

NAPA - Single MC offering described as new.
https://www.napaonline.com/en/p/NMAM2472

There exist other outlets. I read it may be better to choose new and not rebuilt. Yet we see today the Volvo OEM unit is rebuilt with a core charge. So, caveat emptor.
--
Donate NOW! Give your brickboard.com a big DONATION!!! Find the on brickboard pages!

I would be sure that you have fluid moving easily through the system before I jumped to replacing the MC....
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82 242-6.2L; '17 Mazda3; '16 Crosstrek

I guess I will work backwards from the LR caliper and hunt for the blockage.

Sounds solid to me. I will do it, and report the results.
Thanks

Old cars/old brake lines -- the rubber bits can and do break down internally. As that rubber breakdown occurs, bits of the ID of the line can clog the line. The line will still transmit pressure (brakes work) - but when you open the bleeder and try to force fluid through, the bits of broken down line can accumulate and 'clog' the line. Not sure that's what's happening here -- but it's been the reason I've replaced brake lines in the past.

You may need to break the flexible lines at both ends and see if you can isolate where the problem is occurring. Another possibility for a clog is the junction under the rear seat. If you must break the lines open, locate the TINY vent in the top of the reservoir cap. Put a piece of tape over that and fill the reservoir to the very top. If no air can get in the top of the reservoir, virtually no fluid will leak out the bottom when you start breaking things open to check for the problem. If the lines all flow clearly - then the caliper at that corner may be the problem.

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82 242-6.2L; '17 Mazda3; '16 Crosstrek

I have 3 new brake lines, so I will begin by removing the old rears and see if they are clogged. Thanks

Be careful about committing yourself to new flex lines. They aren't rubber except for the outer sheath which protects the nylon line inside.

Depending on how rusty things get where you live, you could be in for a real project if you just decide to replace the flex lines. In other words, loosen the hard line at the caliper first, where it is easy to do, to see if you can then get fluid to bleed more readily. The clog is often just in the bleeder passage in the caliper.
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Art Benstein near Baltimore

A group of chess enthusiasts checked into a hotel and were standing in the lobby discussing their recent tournament victories. After about an hour, the manager came out of the office and asked them to disperse "But why," they asked, as they moved off. "Because", he said, "I can't stand chess-nuts boasting in an open foyer."