[Krsandrsn]

Hey folks!

I have a 1990 Voyager that needs a new proportioning valve (#4485429AB). The part is discontinued. Wondering if anyone has found any work around - for proper rear brake function - they won't bleed properly.

Thanks for the help!

 

[Resource110]

Hey folks!

I have a 1990 Voyager that needs a new proportioning valve (#4485429AB). The part is discontinued. Wondering if anyone has found any work around - for proper rear brake function - they won't bleed properly.

Thanks for the help!

Hey folks!

I have a 1990 Voyager that needs a new proportioning valve (#4485429AB). The part is discontinued. Wondering if anyone has found any work around - for proper rear brake function - they won't bleed properly.

Thanks for the help!

Hey folks!

I have a 1990 Voyager that needs a new proportioning valve (#4485429AB). The part is discontinued. Wondering if anyone has found any work around - for proper rear brake function - they won't bleed properly.

Thanks for the help!

The proportional valve is not a scary as I thought for years. Once I took mine apart I found it was very serviceable. I was able to clean it and replace the o’rings. There was probably a spring in there. I’ll have to dig it out of my spare stash if you need more detail. If you are having a bleeding issue you could add some more details about the problem and we might be able to figure it out.

 

[Krsandrsn]

Sweet thanks! I was thinking that everything needed replacing asap and that this wasn't the best purchase. I'm really loving it when it's not squeaking tho haha!

Here are pics of it's report card. Got new serpentine belt and some units in that system, brake fluid, brake parts(calipers/pads new ish from previous owner), new battery, oil change (got full synth.started leaking[more] and took it back and they replaced it with conventional 🤞), new tires... and yea.

It's definitely a project. Don't want to go broke over this tho!! Haha 😅

Thanks for responding so quick!

 

[Resource110]

Sweet thanks! I was thinking that everything needed replacing asap and that this wasn't the best purchase. I'm really loving it when it's not squeaking tho haha!

Here are pics of it's report card. Got new serpentine belt and some units in that system, brake fluid, brake parts(calipers/pads new ish from previous owner), new battery, oil change (got full synth.started leaking[more] and took it back and they replaced it with conventional 🤞), new tires... and yea.

It's definitely a project. Don't want to go broke over this tho!! Haha 😅 View attachment 65541 View attachment 65542 View attachment 65543

Thanks for responding so quick! View attachment 65544

Ok this is helpful information. Now this is just my opinion mind you from years of working on these cars. These are problems that develop over time because of the age of the car and inadequate maintenance. Things deteriorate and decay over time. I’ve had wheel cylinders rust on the inside from moisture contamination in the old brake fluid and plug the bleeders. I remove the bleeder screw and drill out the corrosion with a 1/16” drill. Ultimately I replaced the brake cylinders because they developed leaks from the rust pitting inside. Did this on the front calipers once too.
You can save alot of $labor by doing this work yourself. Paying a mechanic to do it becomes very expensive because he’ll have to deal with more problems that he’ll encounter just because of the things that have aged and deteriorated in the area he is working in. Some will quote high just to move you along. They know it will require extra time and frustration that they won’t really be able to charge for like when the bill quickly exceeds the value of the car and the customer gets very uncomfortable. You can look on Rockauto.com to get an idea of the availability of parts and what they look like.
I have a Haynes manual that helps explain things. That will at least show you what is involved then you can decide if you are up to tackling ot yourself or not.
By the way in over 40 years of working on my own cars I’ve never encountered a bad proportioning valve, IMHO.

 

[Krsandrsn]

The proportional valve is not a scary as I thought for years. Once I took mine apart I found it was very serviceable. I was able to clean it and replace the o’rings. There was probably a spring in there. I’ll have to dig it out of my spare stash if you need more detail. If you are having a bleeding issue you could add some more details about the problem and we might be able to figure it out.

Ok this is helpful information. Now this is just my opinion mind you from years of working on these cars. These are problems that develop over time because of the age of the car and inadequate maintenance. Things deteriorate and decay over time. I’ve had wheel cylinders rust on the inside from moisture contamination in the old brake fluid and plug the bleeders. I remove the bleeder screw and drill out the corrosion with a 1/16” drill. Ultimately I replaced the brake cylinders because they developed leaks from the rust pitting inside. Did this on the front calipers once too.
You can save alot of $labor by doing this work yourself. Paying a mechanic to do it becomes very expensive because he’ll have to deal with more problems that he’ll encounter just because of the things that have aged and deteriorated in the area he is working in. Some will quote high just to move you along. They know it will require extra time and frustration that they won’t really be able to charge for like when the bill quickly exceeds the value of the car and the customer gets very uncomfortable. You can look on Rockauto.com to get an idea of the availability of parts and what they look like.
I have a Haynes manual that helps explain things. That will at least show you what is involved then you can decide if you are up to tackling ot yourself or not.
By the way in over 40 years of working on my own cars I’ve never encountered a bad proportioning valve, IMHO.

That was very helpful. Thanks a lot!
I want to get to the point that I do the maintenance myself. But as you said, with the age and my lack of experience. I'd rather pay now than more later. Fortunately, I found a 95 caravan at pick n pull so ima salvage from that as much as I can.

OK great because the only valve I saw was in Germany for $200 and it doesn't ship here. So I really hope it isn't that. Just some other clogged arteries from the age.

Would you recommend decreasing the engine? I want to clean it up to get my barring, but afraid more leaks or worse will happen (even if I do waterless and avoid electronics). Or just leave it and get greasy??

✌

 

[Resource110]

Working on a clean engine is always desirable. The valve cover gasket’s are common leakers. I just did mine on the 3.0L. The intake has to come off to gain enough clearance to wiggle the covers off. So you’ll need all the upper gaskets. My general practice is to chip away as much grease and dirt as I can with various implements. Then I blow it off with compressed air. I also use a vacuum cleaner to suck or blow away as much as I can. Then as soon as I crack the part loose before I completely remove the part I scrap brush blow and suck anything else that came loose then I remove the part. Then I’m good to clean the mating surfaces to accept the new gasket, part, etc.
Pressure washing is fine as long as you don’t blast right into the electricals. I tie plastic grocery bags around anything I want to keep dry like the distributor. Spark plug boots should be sealed inside with silicone grease if done right. I’ve never had a problem following this pattern. Good luck

 

[Krsandrsn]

Thanks for reaching out with your expertise. I have more hope than dread now for sure. Each time I check stuff out on the voyager, I get more comfortable. It's really a cool "simple-er" machine.... when you can find the right parts!

I'll be back with more updates thanks Resource110!!

 

[Mr. Minivan]

Hey,

are you sure you do in fact have a broken proportioning valve?
Since your vehicle lacks ABS, is there a Height Sensing Proportioning Valve Assembly connected to your rear left spring, front mounting bracket?

If you have such a Height Sensing Proportioning Valve Assembly and your vehicle was on a hoist with the axles hanging the Valve shuts off the fluid flow quite a lot. Then one might think something is clogged.

If that ain't it, I'd recommend taking out the Valve in the Front. The hard part is not messing up the Lines with seized Flare-Screws. Taking the assembly apart is probably easy.
If you need pictures from an opened valve I could take one apart, probably got one somewhere.

 

[Resource110]

The hard part is not messing up the Lines with seized Flare-Screws.

Mr Minivan makes a very important point. Anytime you are removing tubing fasteners such as the brake line flare nuts at each end or power steering hard line flare nuts, etc. you must use good quality sturdy Flare Nut Wrench. You can use a socket or box end wrench on the bleeder screws or any other "hollow" tube-like fasteners. Don't use an adjustable or open-end wrench because the nut is hollow and deforms under pressure or the wrench fork end can spread and round off the corners of the nut. If you have a sturdy wrench and feel you have to try it anyway, then tap on the wrench end with a small hammer. A quick sharp tap, not bludgeoning. The idea is to shock it loose without so much force it twists the wrench off the nut in one disastrous swoop. Good call Minivan

 

[Resource110]

I was in the shop today and stumbled upon my proportioning valve from an '88 Caravan. It was trickier than I remember so I thought I'd better send some photos and anti-confusers for the curious.

Connections: MC - Master Cylinder, RF- right front caliper, LF - left front caliper, R-rear brake cylinders.
The brake light switch on the top (right side) must be removed first. Then remove the brass fitting at the RF end. Apply some lubricant if the o'ring feels stiff make it slippery and prevent it from tearing.

I used a thin copper wire through the hole in the LF side to push the spool valve (brass piece with the two o'rings) out through the RF side.

The spool valve has what looks like a screwdriver slot on each end. It's not. No screwing around here. I think it's a slot for the brake fluid to bypass the ends of the spool so when it's all the way to one end or the other it doesn't completely block the fluid passage off.

 

[Valhallalla]

Actually, that is not a proportioning valve. It does not alter brake fluid pressure going to any part of the hydraulic system. It is a distribution block that houses the pressure differential switch. First it diagonally splits and isolates the two halves of the brake system: LF with RR and RF with LR. Second, if there is a difference in pressure between the two sides, such as if a hose or wheel cylinder springs a large leak for example, the spool will shuttle to one side or the other, tripping the switch which illuminates the red brake warning light in the cluster. Of course, the driver will probably notice the brake pedal being very low in that case.

On first gen minivans the proportioning valve is of the load sensing type mounted on the rear axle. It varies (limits) pressure to the rear brakes depending upon the ride height to prevent lock up. There is an adjustment procedure for this valve but I have no recollection of what it is.

 

[Resource110]

Actually, that is not a proportioning valve. It does not alter brake fluid pressure going to any part of the hydraulic system. It is a distribution block that houses the pressure differential switch. First it diagonally splits and isolates the two halves of the brake system: LF with RR and RF with LR. Second, if there is a difference in pressure between the two sides, such as if a hose or wheel cylinder springs a large leak for example, the spool will shuttle to one side or the other, tripping the switch which illuminates the red brake warning light in the cluster. Of course, the driver will probably notice the brake pedal being very low in that case.

On first gen minivans the proportioning valve is of the load sensing type mounted on the rear axle. It varies (limits) pressure to the rear brakes depending upon the ride height to prevent lock up. There is an adjustment procedure for this valve but I have no recollection of what it is.

That's a good explanation. It's important to know the difference. I've seen the load sensing type but not all 1st gens have them. The combination valve you are referring to as a distribution block can and may incorporate a proportioning valve. In parts references, they are sometimes identified synonymously creating some confusion but that is the part you would look to if there isn't any other culprit to blame but the lines themselves. Here is a little further explanation

"With all of this being said, it is important for you to know that there are three kinds of proportioning valves used in cars. They are:

• Master Cylinder-Mounted: These valves are located directly on the cylinder and attached to fluid ports located between the cylinder and brake lines.
• Load Sensing: These valves are located directly on the frame at the rear end of the vehicle, with a lever attaching it to the suspension system.
• Combination Valve-Mounted: These valves are part of a larger valve with the metering valve and pressure differential switch. This type of valve is usually mounted to the frame or inner fender below the master cylinder."[How Exactly Does A Brake Proportioning Valve Work | Sun Devil Auto]

Good on you, we're teasing out some good information here

 

[Mr. Minivan]

If a vehicle is equipped with a "height sensing proportioning valve" the splitter in the front ist a "pressure differential switch", and only operates as a switch as described by Resource110.

As far as I recall right now the height sensing proportioning valves are the same on first gen and second gen minivans (unless of course it is equipped with ABS, in that case the prop. valve ist mounted to the ABS-System and there is no height sensing mechanism.)

There is an adjustment procedure for this valve but I have no recollection of what it is.

This is from the "1992 FRONT WHEEL DRIVE ALL WHEEL DRIVE VAN/WAGON" Service Manual.

INSTALLATION AND ADJUSTMENT (FIG. 4)
After installing a new height sensing proportioning valve, bleed both hydraulic circuits at the rear brakes.
The rubber stone/snow shield must be installed whenever the valve is serviced. This shield protects the valve and hydraulic lines from stone impact and the packing of snow and slush.
(1) Lift vehicle with a frame contact hoist or other means so that the rear suspension is hanging free with the shock absorbers disconnected from the axle. Remove the tires and wheels from the rear axle. Be sure that the rear springs do not contact the hoist, or an improper adjustment may result. Loosen both front spring hanger pivot bolts.
(2) Loosen adjustment nut on the actuator assem- bly (Fig. 2). Before adjustment, be sure that actuator assembly hook is properly seated on valve lever.
(3) Pull actuator assembly toward the spring hanger until the valve lever bottoms on the valve body, hold in this position.
(4) Tighten the adjustment nut to 5 Nm (25 in. lbs.) torque. Adjustment is now complete.
(5) Install wheel and tires and connect shock absorbers.
(6) Lower vehicle to floor and with full weight of vehicle on the wheels, tighten both front spring hanger pivot bolts to 129 N􏰄m (95 ft. lbs.) torque. Road test vehicle.

 

[Nickums224]

Hello all! So, I have a very faulty rear height sensing proportioning valve. It’s seized up, and leaking. My mechnic informed me to get a universal proportioning valve with an adjustable knob. I want to just bypass the valve completely, but im not sure what ties to what. It is a 1990 Plymouth Grand Voyager. I’ll submit a picture of the part in question: it looks exactly like the one in the diagram submitted by Mr. minivan. Thanks for any help!

 

[Resource110]

Hello all! So, I have a very faulty rear height sensing proportioning valve. It’s seized up, and leaking. My mechnic informed me to get a universal proportioning valve with an adjustable knob. I want to just bypass the valve completely, but im not sure what ties to what. It is a 1990 Plymouth Grand Voyager. I’ll submit a picture of the part in question: it looks exactly like the one in the diagram submitted by Mr. minivan. Thanks for any help!

I suggest you get the area clean and dry with brake cleaner or hot soap and water if you have to then have someone step on the brakes and watch to see if you can locate exactly where the fluid is leaking out of. It could be those two lines on the bottom have corroded and are leaking. South Main auto repair YouTube channel did a good video awhile back on repairing brake lines. If you can’t afford a mechanic to repair it your auto parts store should be able to provide you with the necessary tools and supplies to get it done right. Of course a repair shop would have that ability but if that’s not an option for you those are my suggestions.
When I was a kid my brakes failed and I ran two stop signs and almost hit a Corvette and the first thing the shop did was get the area really clean so they could spot a pinched line on top of the axle the fluid was running down from
I suggest you get the area clean and dry with brake cleaner or hot soap and water if you have to then have someone step on the brakes and watch to see if you can locate exactly where the fluid is leaking out of. It could be those two lines on the bottom have corroded and are leaking. South Main auto repair YouTube channel did a good video awhile back on repairing brake lines. If you can’t afford a mechanic to repair it your auto parts store should be able to provide you with the necessary tools and supplies to get it done right. Of course a repair shop would have that ability but if that’s not an option for you those are my suggestions.
When I was a kid my brakes failed and I ran two stop signs and almost hit a Corvette and the first thing the shop did was get the area really clean and dry. Only then did they spot the fluid running down from the top of the axle where a brake line had worn through. It was a good lesson.

 

[Nickums224]

I suggest you get the area clean and dry with brake cleaner or hot soap and water if you have to then have someone step on the brakes and watch to see if you can locate exactly where the fluid is leaking out of. It could be those two lines on the bottom have corroded and are leaking. South Main auto repair YouTube channel did a good video awhile back on repairing brake lines. If you can’t afford a mechanic to repair it your auto parts store should be able to provide you with the necessary tools and supplies to get it done right. Of course a repair shop would have that ability but if that’s not an option for you those are my suggestions.
When I was a kid my brakes failed and I ran two stop signs and almost hit a Corvette and the first thing the shop did was get the area really clean so they could spot a pinched line on top of the axle the fluid was running down from
I suggest you get the area clean and dry with brake cleaner or hot soap and water if you have to then have someone step on the brakes and watch to see if you can locate exactly where the fluid is leaking out of. It could be those two lines on the bottom have corroded and are leaking. South Main auto repair YouTube channel did a good video awhile back on repairing brake lines. If you can’t afford a mechanic to repair it your auto parts store should be able to provide you with the necessary tools and supplies to get it done right. Of course a repair shop would have that ability but if that’s not an option for you those are my suggestions.
When I was a kid my brakes failed and I ran two stop signs and almost hit a Corvette and the first thing the shop did was get the area really clean and dry. Only then did they spot the fluid running down from the top of the axle where a brake line had worn through. It was a good lesson.

hello! Thanks for the reply. Yes, I have done that and it is leaking from the proportioning valve through the threads. And the valve itself is malfunctioning, I’m assuming there’s blockage in there and the pressure became too much and eventually popped some rings in there or something and now here we are.. so I just didn’t know if anyone on here has ever bypassed one of these before? The only videos I can find on YouTube are for Toyotas that had similar valves.

 

[George48051]

The proportional valve is not a scary as I thought for years. Once I took mine apart I found it was very serviceable. I was able to clean it and replace the o’rings. There was probably a spring in there. I’ll have to dig it out of my spare stash if you need more detail. If you are having a bleeding issue you could add some more details about the problem and we might be able to figure it out.

Was there a rebuild kit?