My son had to have a "retro" car...a 1988 Volvo 240DL...it looks just like the picture of a "car" drawn by every 5 year-old by the way...

We have replaced both rear shocks, calipers, rotors, parking brake shoes and rotors. We bled the RR caliper without issue. The LR (driver's side) caliper will not bleed as only a few drops of brake fluid expel with each pump of the brake pedal. I have removed both ends of the metal brake line and blown it out with the air compressor. I have removed and blown the hose which connects the metal caliper line to the "flow control" block. Pumping the brake pedal with no line connected to the flow control block produces only a few drops of fluid, so the issue is upstream from this point. Any ideas where to start rather than proceeding one junction point at a time?

Sometimes the learning curve looks like a pretzel....

 

Thanks for reading my post...any information or advice you are willing to share will put a smile on a 17 year-old Volvo owner's face. Every boy has to have his first car...and in this case it also looks like his first drawing of a car...

 

88 has no ABS, so at least you don't have to deal with that. I believe there's a proportioning valve/block in the system, 2 lines from the master cylinder to this proportioning/distribution block, then one line to each brake. the master cylinder has two separate halves with it, each is a separate hydraulic circuit. the parts catalog drawing looks like there's 2 lines to each front brake, and one line to each rear, so I'm not sure how the circuits are divvied up.

but, anyways, I believe I'd make sure BOTH halves of the master cylinder are full of juice first. probably a good idea to test-bleed the front brakes, make sure both circuits to each front brake are good.

 

Thanks for the reply...yes there is a proportioning block mounted to the frame directly below the master cylinder. The right rear caliper is receiving an ample quantity of fluid to bleed properly and the common reservoir atop the master cylinder drops with the bleeding of the RR caliper. We pondered removing all of the lines from the proportioning block (a task as daunting as arm-wrestling an octopus) to give it an internal cleaning and blowing out the line to the LR caliper but hoped to avoid this process if possible.

 

ok, i found a writeup. the split master cylinder, the primary circuit goes to BOTH front brakes and the right rear. the other side, secondary circuit goes to BOTH front brakes (other pipe to each) and to the left rear.

so if you haven't checked BOTH bleeders on each front wheel, its quite possible you've lost one circuit entirely, and need a master cylinder rebuild, and you've been driving around with 50% of your front brakes.

the primary circuit is the rear step of the master and the lower cylinders of the fronts, while the secondary circuit is the front step of the master, and the upper cylinders of both fronts.


oh. if one master circuit has failed, the brake warning light should be lighting up when you step on the brakes, assuming that light works.

 

We haven't tried to bleed the front brakes as we haven't replace the front calipers yet. I'll try to bleed both halves of the front brakes to see if a complete circuit is out; which makes the most sense from what we are experiencing. Thanks for finding the information for us...you may have just put the smile back on the face of a disappointed 17 year-old's face.

 

https://www.fcpeuro.com/products/vol...45-260-1273052

 

I have the exact same problem with my daughter's 2007 c70. I replaced the pads on all corners. However, the driver's side (US) rear caliper gets no fluid. I pulled the rubber line off at the caliper and the rubber line where it meets metal line in the rear wheel well to verify no fluid to that side on the rear. The others all get fluid and pump up. Also, the brake pads on that corner had significantly more pad than the rear passenger corner.

Of course it has abs. But, I have no ABS lights or brake lights lit on the dash. Braking is not that great and the pedal goes further to the floor than I think it should.

There are 2 lines coming off the the MC and going to the distribution block between the brains and pump of the ABS unit. The distribution block has 4 additional lines exiting it and presumably going directly to the 4 calipers. There is no proportioning valve to my knowledge.

I've done a lot of googling and I've posted in the appropriate subforum on this and another site but have received no responses. I was hoping you might have some ideas.

Thanks
Rodney

Edit: I verified that both lines from the MC have fluid when the pedal is pushed. However, line exiting the modulator block that goes to the rear caliper does not have fluid when the pedal is pressed.

 

when I had this problem on my 2000 S40, I wound up replacing the ABS as it had a stuck valve. It didn't throw an ABS code because the controller was actuating the solenoid - just the valve was stuck...

 

Thanks. After all the searching I've done I believe that is what has happened here. I'm going to try a used abs modulator valve and my controller.

 

Did you have any luck with this?


I have the exact same problem with my no 1990 ABS 740, no fluid to one rear caliper. It has the identical "triangle" braking setup (dual piston front calipers, single rears). The only difference is my brake distribution block looks different from the 240's.


I checked for good fluid flow at the junction block to the rear lines, and one wasn't passing fluid. I pushed a blunt probe into that opening in the block, and fluid started flowing. I thought I had it licked, but after reassembling the block, still no fluid from the rear line.


It's almost like I have a clogged line, which seems amazing, but...



EDIT: Searched this thing called the Inter-net and saw this http://s4.zetaboards.com/CJ3B_Bullet...6219&t=1181204


Which said: "You could have blockages in the flexible rubber lines - two on the front and one in the rear - it's very common for the interior of the flex lines to swell and cause blockages. Without disassembing ALL the brake lines on your vehicle and assessing their condition, it's very difficult to give you any accurate determination of the condition of the INTERIOR of the brake lines."


So I'm thinking I need to replace the short rubber lines all around (they might be original equipment..!)

 

Found the problem!


It was a bad flexible hose. Couldn't get the fitting off, so I cut the line directly in front of the fitting and presto!



...THE DOT3 MUST FLOW.