The RH pedal on my upright piano has developed an annoying squeak over the course of today. Is there a straightforward DIY remedy (eg WD40), or should I call in the tuner?

i had that trouble!!
Use the good old WD40!!!

If you can tell exactly whereabouts it's squeaky, a squirt of WD40 should do the trick - it just wouldn't be a good idea to spray it about wholesale !

Oh good. My husband is good with that sort of thing, and he thought it would be fairly simple to do as well.

PS I meant to say, thanks for the help.

WD40 will solve it for a while , but if hubby has some cycle oil/sewing machine oil it would probably stave off the squeak longer. I get the same problem.

WD40 is good for a temporary thing, but it would be easier to call the tuner and stop it for good. My tuner sorted my pedal yesterday and gave me a long explanation of why it does squeak. Can't remember a thing though

Well, the tuner's not due for another few months, so we'll try the suggestions here for a temporary fix, and ask the tuner when he comes. Thanks again to all for the help.

Did the WD 40 do the trick?
I do remember my husband being called to try to sort a squeaky pedal once - he's not a piano technician, but one of his friends does piano repairs for Broadwoods, and sent him off to do this job. I seem to remember the keyboard had to come out of this particular piano in order to get the squeak fixed...

A bit of metal will be rubbing against some leather or cloth or something.

The pedal mechanism is purely mechanical, so you cannot do it any damage unless you bend something metallic or break something wooden. You are quite safe to take things apart so long as you note how to put them back together again.

So experiment and see if you can find the source of the squeak. If you find it, then some Vaseline will cure it.

My dad put some WD40 on the pedal once but mucked it up. We had to get a tuner to do it in the end.