Hey guys, I'm hoping someone can point out something that I'm missing here. This is only the 2nd volvo i've ever worked on, long time Audi guy here.

I recently came into a 86' 240 GL that was sitting due to zero brake pressure. I have done a good bit of work already, I replaced the front right caliper which had a broken bleeder and was pissing fluid from it, new caliper went on smoothly. Assumed the master cylinder was dead since pedal still went to floor, put in a new/reman master cylinder from oreilly's, bench bleed it, bleed it on the car, still NO brake pressure, goes right to the floor.

Is there something else in these cars that would allow this? I'm not familar with the braking setup on these cars, I'm noticing a huge round object attached before the master, is that the booster? Could that be causing zero brake pressure? Also, I'm getting very little brake fluid to come out of the left rear caliper, not sure if that caliper is bad as well, or perhaps the new master cylinder is DOA.

Anything else I might be missing that needs attention? Totally stumped, never had so many issues with brakes! Please help!

 

Also I should mention, the front drivers side caliper, someone snapped off one of the bleeder screws (front caliper has 3)...they broke off the inside lower bleeder, however it's not leaking fluid from that bleeder. I'm wondering if perhaps air is getting inside that broken bleeder perhaps?

 

if you pump the brake pedal 5-10 times does it even build pressure (car off)

if it does then so far so good, press the pedal hard for about 30-60 seconds, does it slowly move to the floor?

if it doesn't, can you see any leaks? does the brake fluid level drop after pumping the brakes like this?


as far as the broken bleeder valve, that should still be sealed, however were you able to bleed that caliper? if not there is likely a massive amount of air in the system

 

I can pump the brakes 20 times (car off) and it makes no pressure still. It will pretty much go right to the floor with little effort, the only slight improvement is if i pump the pedal VERY fast there is some resistance, but normal pumping, no pressure build, will go to the floor.

The system is holding fluid, no more leaks, the res stays topped off.

Regarding broken bleeder: I can get fluid out of the lower-outside bleeder, but no fluid comes from the top bleeder. Do you think i'll be able to get this caliper working with only 2 bleeders, or should we consider a new caliper if I can't extract/replace that bleeder?

 

if a new master cylinder isn't building pressure while nothing is leaking out, either the brake lines are all connected wonky, or that new master cylinder is defective.

(from memory, whihc could be rusty), there's 2 brake circuits, one is the top half of both front cylinders, and one rear cylinder, the other is the bottom half of both front cylinders, and the other rear cylinder. this is so that if a circuit fails, you still have 3 wheels of braking, albeit with half force in the front. if the pedal is going to the floor no matter how many pumps, something is seriously fubar in how its connected, OR that new (rebuilt?) master cylinder is completely bad.

 

Yeah, my hunch is telling me we got a DOA master cylinder, it's a rebuilt one so it's very possible. I'm picking up another MC tonight and we'll try that one out. I'll report back once that one is in. Never had so many issues with a brake system, very bizarre. Fingers crossed.

 

you make be able to get that broken bleeder out with a bolt extractor like this

https://images-na.ssl-images-amazon....SR248,320_.jpg

Otherwise a new caliper would be required
as I can see, you are already replacing the master cylinder under suspect that its DOA, that too is a god step

 

You mention you replaced one front caliper? I always replace in pairs. How are the rear calipers? Have they been replaced? Have you bled them?

If the fluid is not going down at all when you pump the brakes then indeed there is something wrong with the MC. Just on a hunch, where is the bleeder screw on the rear calipers? Is it toward the top or near the bottom of the caliper. The rear calipers can be installed on the wrong side of the car making them impossible to bleed properly. If the bleeder screw is toward the bottom, then they need to be swapped.

 

The rear calipers both have the bleeder at the top, so they are installed correctly.
I did not replace both front calipers, just the pass side.
Didn't get a chance to work on the volvo last night but will certainly replace the MC (again) tonight, picked up another reman from autozone this time, we'll see what it does. I'll post results with the autozone MC.

 

Do you know that there is spasific sequence for bleeding the brakes? Being a caliper was replaced the complete system needs to be bleed.

 

This post seems strange as the early braking system is pretty simple in design. This is not an ABS unit so it is just a normal vacuum assist split system. We assume all components and lines have been checked. When you removed all of the calipers and seated the pistons did you have any problems. was brake fluid coming out of all of the brake lines/hoses. Has the bias valve been checked and centered. Did you check the brake booster for leaks. Is the new MC the same as the old and was it bench bled correctly. Also how did you bleed the system , was it a power bleed or hand vacuum pump or the old fashion way of pumping the peddle. At this point there are to many questions open so if it were me I would start back at the beginning. Pull all 4 calipers and reseat the pistons and replace all of the bleeders (I would install SPEEDBLEEDERS). Replace the brake hoses and install the calipers with new brake pads. Replace the MC and make sure the rod length is correct and it was bench bled. Fill the system start the bleeding process (RR,LR,RF,LF) making sure the MC res. is kept full. I assume the peddle and rod inside the car is working correctly. It doesn't seem possible that you can have that much air in the system unless you have a large leak.

 

3rd master cylinder in, still no brake pressure. Jagtoes I agree, this is by far the strangest issue i've ever seen on such a simple braking system. I've rebuilt Audi motors with less complication.
Back to the drawing board i guess.

 

Couple things to note: with the 3rd MC in, i can create "some" brake pressure with the car off, however if i push hard enough it will still go to the floor.
Once I start the car, the pedal goes to the floor with zero effort. I'm starting to think this is a vacuum issue with how the brakes respond with the car running. I have looked at all the vacuum lines high and low and everything looks good.
I gotta say for the first time in many years, I'm totally stumped.

 

Pull the brake booster and check the brake peddle linkage to verify it is working correctly. Check the diaphragm and make sure it is operating the MC. Think about it as in order for you to get no pressure either you have a massive leak or there is a disconnect between the brake peddle and the MC. Also crack open the RR caliper bleeder and see if brake fluid comes out and the container looses fluid.

 

I agree with jagtoes here, open the booster. You may want to disconnect the vac line from the booster and try it before opening it up if for laughs and giggles only. If you lift the car up, and have someone press the brakes, can you turn the wheels? can you turn only one, or some? this may narrow it down a bit.

I have seen very old fuel lines cause this also. With added hydraulic pressure they can expand. Steel brake lines will prevent this. Now these Volvos are mostly hard line with very little flexible rubber, so I don't suspect this but for curiosity, have sone pump the breaks and watch the brake lines. Are they expanding? a little is normal but if one has some sort of bubble in it or something perhaps this could be the problem.I bring this up because you can get "Some" pressure but not much

Lastly, I am still thinking there is air in the system so, you obviously know your way around a car, but my question is, how exactly are you flushing the brakes? what is your process. I recommend the Power Bleeder form IPD as it will fully flush everything out.

 

Once you have done all that, check this next:

The Brake Proportioning Valve

each brake circuit has one, so for you that’s either 2 or 3 I believe. it balances the pressure between the front and back brake sets and some cases the left and right front wheels. The valves should all be built into a single block. They very rarely go bad and may just need to be cleaned and “reset"


Disconnect the plug contact and screw out the warning switch so the pistons inside the valve may return to their normal position.
Repair and bleed the faulty hydraulic circuit.
Screw in the warning switch and tighten it to 10-14 ft. lbs. (14-19 Nm).
Connect the plug contact.

You may want to remove the whole block and clean it up with some clean brake fluid while you are at it but may not be necessary. At the same time, they only cost about $60
https://www.eeuroparts.com/Parts/410...AxQaAlHY8P8HAQ

 

Thanks for all the input fellas, I'm with you on all that. And i did already take a look at the proportioning valve, no leaks, looks pretty clean.
Also, I was able to find another brake booster locally, a used one though, I swapped it in for kicks, no difference. What that means who knows, could I have 2 bad brake boosters, possibly.
My hunch really tells me I'm dealing with bunk re manufactured master cylinders. So I just ordered a brand new one (NOT reman) so we'll try my luck with yet another MC. Will follow up on Wednesday when the NEW MC gets here.

 

Just because you can get fluid from the caliper does not mean that there is no air in the system. Fix the bleeder screw or replace the caliper. Flush the system completely. You could try using fluid of a different color to "Know" that the line is cleared of air. A couple quarts of fluid is cheaper than replacing all of the hard parts. The proper order is the same as 99% of brake systems, start with the wheel farthest from the Master Cylinder and proceed to the next farthest, etc. There are so many places in the system where air can be trapped that just a few pumps to bleed is not enough. When I bleed the system after opening the system, I make sure all of the fluid is replaced, not just bled until air bubbles stop. If you don't want to buy a pressure bleed system, them make a simple bleed assist using two lengths of vinyl line and a one way check valve into a quart jar. Use a nylon tie to keep the line on the bleed screw and punch 2 holes it the jar lid. Sick the line to the bottom of the jar, and have the one way valve inline close to the caliper (to allow less spillage when disconnected.) You can epoxy a plastic nipple in the jar if you are going to do this a lot. Here are some examples of the one way check valve:

https://premiumaquatics.com/products...FQp3fgodwRcOAQ

https://www.amazon.com/Non-Return-Pe.../dp/B00Z6KLUQW

 

Here is the check valve and I use these on all of my cars. Easy to do a brake fluid flush every 30K miles.
Speed Bleeder Bleeding Brakes Bleeding Motorcycle Brakes Automotive Bleeder Screw Brake Bleeder

 

I will ask this question again. Are you bleeding the system as per the diagram ?? If you open any line the sequence must be followed. If you don't follow it you will not get a pedal.fyi years back I had one that would not bleed. We raised the rear axel up about 2 feet and left it over night.bleed out ok after that. Another tip run a hose from your port into a bottle with the end covered with brake fluid.watch for the bubbles.