Volvo RWD 200 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 11/2009 200 INDEX

[<<]  [>>]


THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD




  REPLY TO THIS MESSAGE    PRINT   SAVE 

holy crap! whats wrong with my brakes? 200 1984

So after changing out my junction block in my brakes, my "brake failure" light came on. After a few brake checks it went out, but it comes on every now again, no big deal. Well anyway, the other night i was waiting for some friends in front of the garage they were parked in and I noticed that when I keep constant pressure on the brake pedal, it slowly goes to the floor, and the light comes on. I did this a few times in a row, and the light came on every time. Now the interesting part is, I'm not losing any fluid while this is happening. Had I lost fluid, I would just call in an RMA on the block, but I don't know where to go from here. As always, I greatly appreciate the info.








  REPLY TO THIS MESSAGE    PRINT   SAVE 

holy crap! whats wrong with my brakes? 200 1984

Wow. Thanks guys. I don't htink I've had a response that fast. Looks like I have a "day off" of volvo zen ahead of me. I just blew a wheel bearing too.








  REPLY TO THIS MESSAGE    PRINT   SAVE 

Changing the MS and not having to bleed the sstem again. 200 1984

Of all the seemingly simple jobs on 240 upkeep, I absolutely hate to bleed brakes. Lusy track record.

Therefore here is my MC change method to avoid that task.

Combine the job with replacement of front pads, if appropriate.


Overview: (1) Set things up to minimize the time during which the brake lines are actually disconnected fromthe MC. There will be a small amount of air get into the lines, but it should all be in the vertical lines from the MC down to the junction block.

(2) After installing the MC, do the front pad job. The action of pushing the pads back into the calipers will push a good bit of fluid back up into the MC (in fact, you should wrap the MC filler cap area with an old towel or smething, to keep fliud off the paint). The fluid where the air bubbles are located will be pushed back up, thus the air bubbles are eliminated. Neat. Works for me.


You should bench bleed the MC first.

Here's how (1) gets done: First loosen the brake line fittings a good bit and then retighten them finger tight. Then remove the nuts holding the MC onto the car. 17mm, I think. Next - helps to have a helper here - remove the brake lines, hand the old MC to helper, put new one on studs and finger tighten the lines.

Nuts and fittings can be wrench tightened later, just get the lines closed off.

Tighten the nuts holding MC to car, then the flare fittings.

Good Luck,

Bob

:>)









  REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

holy crap! whats wrong with my brakes? 200 1984

Master cylinder failure is quite common when brakes are bled. The master cylinder seal gets pushed onto an area that it hasn't touched before, and the roughness damages the seal, so fluid starts to escape past it.

Limiting the pedal's travel when bleeding, or pressure bleeding the system can prevent this from happening.








  REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

holy crap! whats wrong with my brakes? 200 1984

My two cents,

I agree with a bad master cylinder. The seals in the master cylinder are allowing the brake fluid to sneak by when you are lightly pressing on the pedal. Once the pedal starts to sink you can stomp on the brakes to create enough force for the seals to actually stop and push the fluid inside the master cylinder but once the pressure on the brake pedal becomes light enough it will once again sink to the floor. This is very dangerous and should be repaired ASAP. Sound like you have a weekend job to do. Good Luck!

Sincerely,
--
Julio Meza

1979 264GL B27F 122K

Features Added:

BW55 To M46, Central Locking System, 25mm IPD Front Sway Bar, 81+ Dash W/ Oil & Ambient Temp Gauges In C, Oil Pressure, Volts

Next Project:

+Cruise Control








  REPLY TO THIS MESSAGE    PRINT   SAVE 

Master Cylinder failure 200 1984

Classic Master Cylinder failure. The seal around the piston is leaking, so fluid from the high pressure side seeps through to the low pressure side -- it's not going anywhere, so there's no overall loss of fluid, but the pedal drops "as if" a caliper was leaking because there's a decreasing volume of fluid on the high pressure side.
BTW, this often happens (I see this effect described on this board at least once a week) with an older car when its owner works on (i.e., bleeds) the brakes -- in the process of doing so, at some point the master cylinder's piston advanced (e.g., pedal was pushed, perhaps when you finished your job) a little too far and its piston's seal slid along a normally unused, rusty portion of the cylinder, scraping the seal and ruining it.
Just replace the master cylinder.
Good luck.








  REPLY TO THIS MESSAGE    PRINT   SAVE 

holy crap! whats wrong with my brakes? 200 1984

same thing happened to a guy in his airplane i knew, master cylinder shot.








  REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

holy crap! whats wrong with my brakes? 200 1984

The master cylinder has failed.

Randy







<< < > >>



©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.