Revitalised Wiper Delay

Tom W

Active Member
#61
I vaguely remember reading that there’s supposed to be a plastic cap on the end of the plunger, where the linkage contacts it.
 

cobraboy

Well-Known Member
#62
In an ideal world with capsule in your hand you need to be able to compress the plunger and put your finger on the end of the vacuum stub and have the plunger stay compressed. By then gradually releasing your finger control the rate at which the plunger is released, then you will know that the motor end works. If you still do not get a delay then the fault lies in the pipe or white knob.
Tom, yes the plunger does have a cap on it.
 
#63
Ah, no cap on my plunger. I shall have to devise something suitable. The nylon tip intended for the gear selector finger might do the job, or might be too big. Would anyone be willing to post a photograph of the cap in situ? And how thick is the part of the cap between the plunger and the plate on the linkage, roughly? That could affect the plunger throw and the 'head' of vacuum generated.

Thanks again, John
 
#64
Update – forget the selector finger tip idea, it's too big. I've found a piece of hard nylon speedo drive from a Hillman Imp, with a hollow shaft and a mushroomed end, which should do the job with some modification. So don't worry about a photo, but what would be useful to know is either that thickness of the cap beyond the metal end of the plunger rod, or failing that what clearance – if any – there is between the cap and the plate on the wiper drive when the plunger is fully extended and the plate is furthest away. Either dimension will enable me to make my home-made cap to the right thickness.

Thanks yet again, John
 

Tom W

Active Member
#66
That looks different to mine. On my car it’s actuated by a crank. Guess it’s the difference between the linkage wiper mechanisms and those with the flexible cable and wheel boxes.
 
#67
Many thanks for the pic. Mine is different, too, actuated by the linkage crank like Tom W's. I guess I'll need to devise a thickness of cap that just activates the contacts at maximum throw without crushing the mechanism. I've fitted a piece of sponge and soldered together a contact terminal which had split in two. The switch now works with the plunger's movement, and when connected to the vacuum pipe the plunger's gentle and slow return is credibly variable with the white knob on the steering column. So it's looking good.

I love the way that the available range of delay times is dictated entirely by the density and construction of a piece of sponge. Who needs electronics?
 
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cobraboy

Well-Known Member
#68
Strange that mine is a '72 and so is yours, so I was assuming we had the same type of delay system. Perhaps as well I did throw up a photo otherwise things might have gone skew wiff

Actually it is the white knob operated vacuum release that varies the delay times, the sponge just captures the vacuum, but I know what you are saying, it's simple and it works, which is great.
 
#69
Now refitted and it works! The range of delays isn't quite right, though, variable from almost none to maybe 4sec. I could fit a thicker cap of some sort to increase the plunger stroke, by making it stay in contact with the plate on the linkage for longer, but I suspect the 48-year-old vacuum line and white knob might not be entirely leakproof. The delay capsule itself seems vacuum-tight if I push the plunger in and press a finger over the pipe stub. The plunger stays in position as long as the finger stays there.

Anyway, everything on my Rover now works – the last fix was the clock, again with this forum's help, which had done the usual fusible-link melt. So it's a milestone day.
 

Phil Robson

Well-Known Member
#70
A great thread!

I've serviced BOP's wipers which were only working on one speed. Now they are working well on slow & fast but the delay isn't working yet. From all your experiences, it looks like it will be the governor / foam that needs repairing & I'll investigate this :)
 
#71
A great thread!

I've serviced BOP's wipers which were only working on one speed. Now they are working well on slow & fast but the delay isn't working yet. From all your experiences, it looks like it will be the governor / foam that needs repairing & I'll investigate this :)
Glad the post is still helping others out. Can’t believe it has been nearly seven years since I posted this!!!
 
#74
Any idea why I cant see any pics on page 1 please? Am a member and logged in...
thanks.
Photos are hosted on my own web space and I have noticed that occasionally they disappear from this site although the original are still there. I can’t really explain it.
 
#75
Just checked my iPad and no pictures showing. Next checked my work pc and did show pictures. Now I’ve checked my iPad again and they are all there. Bloomin’ computers...
 

Phil Robson

Well-Known Member
#78
Thanks to the info on here, BOP's wipers work as they should (slow, fast & variable delay) for the first time in my 11 year ownership :cool:. This was the state it was in when I started:

IMG_8043.JPG

IMG_8045.JPG

I haven't had the motor apart, but have done everything else noted; de-greasing & re-greasing the mechanism & stripping the delay governor & replacing the non-existent foam. I also replaced the broken bobbin mountings with some I'd bought for this purpose many many years ago (how I found them again, I don't know!)

IMG_8098.JPG

I still haven't worked out how you tighten the clamp screw in situ... (access is nigh on impossible).

It's all back in now. I couldn't get the delay to work properly at first even though I'd fixed the vacuum side of things. Not being a great one for car electrics, I was a bit stumped but by watching it operate I came to the conclusion that it wasn't working in the correct 'cycle'. The answer was that I'd got the yellow & purple wires the wrong way round :rolleyes:. This is now the correct way:

IMG_8143.JPG

:cool::cool:
 

Phil Robson

Well-Known Member
#79
Thanks to the info on here, BOP's wipers work as they should (slow, fast & variable delay) for the first time in my 11 year ownership :cool:.
I shouldn't have spoken so soon - out in the rain yesterday all worked fine, except that this is where the wipers decide to stop whilst delaying....

IMG_8146.JPG

Any ideas, please?
 
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